# Ero Announces Result of Year-Long Value-Creation Initiative at Xavantina, Commences First Gold Concentrate Sales in Q4 2025 Canonical Atlas analysis: https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2 Original source: https://money.tmx.com/en/quote/ERO/news/5734789895881453/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc Publisher: tmx Original announcement: 2025-11-04T12:00:00.000Z Analysis by Minestarters Atlas Atlas analysis published: Unknown date Atlas analysis updated: Unknown date - Company: Ero Copper Corp. - Ticker: ERO - Exchange: TSX - Region: Mato Grosso State, Brazil - Primary commodity: Gold - Secondary commodities: None reported - Document categories: Resource update, Metallurgy - Extracted: 2026-09-13 22:55:42 UTC Narrative sentiment: 0.80 · Bullish ## Minestarters Atlas summary Ero Copper Corp. announced an updated NI 43-101 compliant mineral reserve and resource estimate for its Xavantina Operations in Brazil, effective June 30, 2025. The update includes meaningful increases in Measured and Indicated gold resources, now totaling 664,000 ounces, and a maiden inferred mineral resource of 29,000 ounces from high-grade gold concentrates stockpiled since 2012. The company has commenced initial sales of these concentrates and expects to significantly bolster gold sales over the next 12 to 18 months. Reasoning: Ero Copper announced a new NI 43-101 compliant resource estimate for its Xavantina Operations, showing meaningful increases in Measured and Indicated gold resources and a maiden inferred resource for gold concentrates from stockpiles. This, combined with the commencement of gold concentrate sales, represents significant value creation and de-risking for the project, supported by operational improvements and ongoing exploration success. - Positive factor: Significant increase in Measured and Indicated gold resources, enhancing project confidence and potential for future reserve conversion. - Positive factor: Maiden inferred mineral resource estimate for high-grade gold concentrates from stockpiles, representing new value unlocked from existing operations. - Positive factor: Commencement of gold concentrate sales, providing immediate monetization of a previously unmonetized asset. - Positive factor: Successful transition to mechanized underground mining, indicating operational improvements and efficiency. - Positive factor: Ongoing exploration efforts continue to extend mineralization, suggesting further growth potential. - Positive factor: Resource estimate is NI 43-101 compliant and signed off by a Qualified Person, ensuring high reporting standards. Facts used in scoring: 14 ## Classification and evidence **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: The mineral reserve and resource estimate for the Xavantina Operations is an update of its National Instrument 43-101 \(“NI 43-101”\) compliant mineral reserve and resource estimate. Evidence · text > National Instrument 43-101 \(“NI 43-101”\) compliant mineral reserve and resource estimate **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: The 2025 mineral reserve and mineral resource estimates are prepared under the supervision of and verified by Mr. Cid Gonçalves Monteiro Filho, who is a “qualified person” within the meanings of NI 43-101. Evidence · text > prepared under the supervision of and verified by Mr. Cid Gonçalves Monteiro Filho, SME RM \(04317974\), MAIG \(No. 8444\), FAusIMM \(No. 329148\) and Manager, Resources & Reserves of the Company who is a “qualified person” within the meanings of NI 43-101. **Category Upgrade** Polarity: positive Definition: Resource confidence improved — Inferred upgraded to Indicated, or Indicated to Measured. De-risking signal. Why it applies: The ongoing exploration efforts resulted in meaningful increases in overall measured and indicated resources. Evidence · text > meaningful increases in overall measured and indicated resources **Contained Metal Growth** Polarity: positive Definition: True scale improvement — contained metal ounces/tonnes increased vs prior, accounting for both tonnage and grade changes. Why it applies: The overall measured and indicated resources now total 664,000 ounces, indicating growth in contained metal. Evidence · text > meaningful increases in overall measured and indicated resources, which now total 664,000 ounces **Maiden Resource** Polarity: neutral Definition: First formal MRE for the project — establishes baseline but typically exploration-stage with high Inferred component. No prior estimate exists, so every change band is not applicable. Why it applies: A maiden inferred mineral resource estimate of approximately 29,000 ounces was determined for high-grade gold concentrate. Evidence · text > maiden inferred mineral resource estimate of approximately 29,000 ounces \(24,000 tonnes at 37.4 grams per tonne \("gpt"\)\) in high-grade, marketable gold concentrate **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: The document provides an update of its National Instrument 43-101 compliant mineral reserve and resource estimate. Evidence · text > update of its National Instrument 43-101 \(“NI 43-101”\) compliant mineral reserve and resource estimate **Underground Mining** Polarity: neutral Story-specific tag Definition: No canonical definition is currently available. Why it applies: The resource estimate was constrained using a minimum stope dimension and a cut-off based on underground mining costs, and the mine plan incorporates the Sublevel Stoping \(SLS\) mining method. Evidence · text > a cut-off of 1.46 gpt based on underground mining and processing costs of US$107 per tonne and a gold price of US$2,500 per ounce. The 2025 mine plan incorporates the Sublevel Stoping \(SLS\) mining method **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: A cut-off of 1.46 gpt based on underground mining and processing costs was used for the mineral resource estimate. Evidence · text > a cut-off of 1.46 gpt based on underground mining and processing costs of US$107 per tonne and a gold price of US$2,500 per ounce **Mill Route** Polarity: neutral Definition: Processing via mill or concentrator \(CIL, CIP, tank leach, flotation\). Why it applies: the document describes a flotation route \("concentrate"\) ## Extracted facts Stored fact records: 14. Some facts used in scoring do not have a stored record. ## Resource Estimates (14) ### proven [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-0) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: reserve - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:8d71baefcfddfb86eb39 - Deposit or zone: Santo Antônio Vein - Mining method: combined #### Resource Data - Category: proven - Tonnes: 221000 - Grade: 6.48 - Grade Unit: g/t - Contained Metal: 46.1 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The Proven Reserve for Santo Antônio Vein shows a high-grade, economically viable portion of the resource, contributing to the overall project confidence. - Positive factor: Proven Reserve category indicates high confidence in economic viability. - Positive factor: Grade of 6.48 g/t Au is high-grade for underground gold mining. Evidence · table > 6.48 Context: 221 #### Tags used in scoring **Proven Reserve** Polarity: positive Definition: Measured Resource with demonstrated economic viability after applying modifying factors. Why it applies: category is "proven" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### probable [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-1) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: reserve - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:c49a4b9bcbe2d88ba817 - Deposit or zone: Santo Antônio Vein - Mining method: combined #### Resource Data - Category: probable - Tonnes: 1793000 - Grade: 6.98 - Grade Unit: g/t - Contained Metal: 402.5 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The Probable Reserve for Santo Antônio Vein represents a substantial, high-grade, and economically viable portion of the resource, contributing significantly to the project's overall value. - Positive factor: Probable Reserve category indicates good confidence in economic viability. - Positive factor: Grade of 6.98 g/t Au is high-grade for underground gold mining. - Positive factor: Significant contained metal of 402.5 koz Au. Evidence · table > 6.98 Context: 1,793 #### Tags used in scoring **Probable Reserve** Polarity: positive Definition: Indicated Resource with demonstrated economic viability after applying modifying factors. Why it applies: category is "probable" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### measured [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-2) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: resource - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:506766ea5bb6aaaea7e3 - Deposit or zone: Santo Antônio Vein - Mining method: combined #### Resource Data - Category: measured - Tonnes: 312000 - Grade: 8.05 - Grade Unit: g/t - Contained Metal: 80.8 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The Measured Resource for Santo Antônio Vein demonstrates high geological confidence with a world-class grade, providing a strong foundation for future reserve conversion. - Positive factor: Measured Resource category indicates high geological confidence. - Positive factor: Grade of 8.05 g/t Au is world-class for underground gold mining. Evidence · table > 8.05 Context: 312 #### Tags used in scoring **Measured Resource** Polarity: positive Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves. Why it applies: category is "measured" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### indicated [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-3) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: resource - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:3d3597fa2aff6f701cb0 - Deposit or zone: Santo Antônio Vein - Mining method: combined #### Resource Data - Category: indicated - Tonnes: 1949000 - Grade: 8.75 - Grade Unit: g/t - Contained Metal: 548.2 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The Indicated Resource for Santo Antônio Vein shows a substantial, high-grade resource with good geological confidence, contributing significantly to the overall increase in M&I resources. - Positive factor: Indicated Resource category indicates good geological confidence. - Positive factor: Grade of 8.75 g/t Au is world-class for underground gold mining. - Positive factor: Significant contained metal of 548.2 koz Au. - Positive factor: Meaningful increases in overall measured and indicated resources. Evidence · table > 8.75 Context: 1,949 #### Tags used in scoring **Indicated Resource** Polarity: positive Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves. Why it applies: category is "indicated" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### inferred [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-4) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: resource - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:4124e3c018bcfb518b1b - Deposit or zone: Santo Antônio Vein - Mining method: combined #### Resource Data - Category: inferred - Tonnes: 1057000 - Grade: 9.31 - Grade Unit: g/t - Contained Metal: 316.5 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The Inferred Resource for Santo Antônio Vein shows high-grade potential but requires further drilling to upgrade its confidence category for economic studies. - Positive factor: Grade of 9.31 g/t Au is world-class for underground gold mining. - Negative factor: Inferred Resource category has lower geological confidence and cannot support economic studies alone. Evidence · table > 9.31 Context: 1,057 #### Tags used in scoring **Inferred Resource** Polarity: negative Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone. Why it applies: category is "inferred" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### probable [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-5) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: reserve - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:f9b01d7b67de146a3f6e - Deposit or zone: Matinha Vein - Mining method: combined #### Resource Data - Category: probable - Tonnes: 82000 - Grade: 6.65 - Grade Unit: g/t - Contained Metal: 17.6 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The Probable Reserve for Matinha Vein is a smaller, but high-grade and economically viable contribution to the overall reserve base. - Positive factor: Probable Reserve category indicates good confidence in economic viability. - Positive factor: Grade of 6.65 g/t Au is high-grade for underground gold mining. Evidence · table > 6.65 Context: 82 #### Tags used in scoring **Probable Reserve** Polarity: positive Definition: Indicated Resource with demonstrated economic viability after applying modifying factors. Why it applies: category is "probable" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### indicated [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-6) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: resource - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:d0dd25bafa0674cf0a28 - Deposit or zone: Matinha Vein - Mining method: combined #### Resource Data - Category: indicated - Tonnes: 98000 - Grade: 11.11 - Grade Unit: g/t - Contained Metal: 35.1 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The Indicated Resource for Matinha Vein, though small, boasts a world-class grade, adding high-quality ounces to the resource base. - Positive factor: Indicated Resource category indicates good geological confidence. - Positive factor: Grade of 11.11 g/t Au is world-class for underground gold mining. Evidence · table > 11.11 Context: 98 #### Tags used in scoring **Indicated Resource** Polarity: positive Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves. Why it applies: category is "indicated" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### inferred [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-7) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: resource - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:d0563015cc1f8a3f5e78 - Deposit or zone: Matinha Vein - Mining method: combined #### Resource Data - Category: inferred - Tonnes: 84000 - Grade: 7.26 - Grade Unit: g/t - Contained Metal: 19.7 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The Inferred Resource for Matinha Vein, while high-grade, requires further drilling to increase confidence and support economic evaluation. - Positive factor: Grade of 7.26 g/t Au is high-grade for underground gold mining. - Negative factor: Inferred Resource category has lower geological confidence and cannot support economic studies alone. Evidence · table > 7.26 Context: 84 #### Tags used in scoring **Inferred Resource** Polarity: negative Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone. Why it applies: category is "inferred" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### inferred [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-8) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: resource - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:4349a65fa34205c1e770 - Deposit or zone: Gold Concentrates - Mining method: combined #### Resource Data - Category: inferred - Tonnes: 24000 - Grade: 37.41 - Grade Unit: g/t - Contained Metal: 29.3 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: Xavantina laboratory, ALS Brasil Ltda., ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: This maiden inferred resource for high-grade gold concentrates from stockpiles represents a significant new value stream for the company, with sales already commencing. - Positive factor: Maiden inferred mineral resource estimate for gold concentrates, representing new value unlocked. - Positive factor: Exceptional grade of 37.41 g/t Au, indicating high-value material. - Positive factor: Commencement of sales from this material, providing immediate monetization. Evidence · table > 37.41 Context: 24 #### Tags used in scoring **Inferred Resource** Polarity: negative Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone. Why it applies: category is "inferred" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### proven [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-9) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: reserve - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:f09a85fe0047c35efa3d - Deposit or zone: Total Xavantina Operations - Mining method: combined #### Resource Data - Category: proven - Tonnes: 221000 - Grade: 6.48 - Grade Unit: g/t - Contained Metal: 46.1 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The total Proven Reserve for Xavantina Operations confirms a high-confidence, economically viable portion of the overall project. - Positive factor: Proven Reserve category indicates high confidence in economic viability. - Positive factor: Grade of 6.48 g/t Au is high-grade for underground gold mining. Evidence · table > 6.48 Context: 221 #### Tags used in scoring **Proven Reserve** Polarity: positive Definition: Measured Resource with demonstrated economic viability after applying modifying factors. Why it applies: category is "proven" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### probable [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-10) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: reserve - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:c8469c80d8066308c17a - Deposit or zone: Total Xavantina Operations - Mining method: combined #### Resource Data - Category: probable - Tonnes: 1875000 - Grade: 6.97 - Grade Unit: g/t - Contained Metal: 420.1 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The total Probable Reserve for Xavantina Operations represents a substantial, high-grade, and economically viable portion of the project's overall value. - Positive factor: Probable Reserve category indicates good confidence in economic viability. - Positive factor: Grade of 6.97 g/t Au is high-grade for underground gold mining. - Positive factor: Significant contained metal of 420.1 koz Au. Evidence · table > 6.97 Context: 1,875 #### Tags used in scoring **Probable Reserve** Polarity: positive Definition: Indicated Resource with demonstrated economic viability after applying modifying factors. Why it applies: category is "probable" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### measured [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-11) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: resource - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:12935c7c96e573c67c06 - Deposit or zone: Total Xavantina Operations - Mining method: combined #### Resource Data - Category: measured - Tonnes: 312000 - Grade: 8.05 - Grade Unit: g/t - Contained Metal: 80.8 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The total Measured Resource for Xavantina Operations demonstrates high geological confidence with a world-class grade, providing a strong foundation for future reserve conversion. - Positive factor: Measured Resource category indicates high geological confidence. - Positive factor: Grade of 8.05 g/t Au is world-class for underground gold mining. Evidence · table > 8.05 Context: 312 #### Tags used in scoring **Measured Resource** Polarity: positive Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves. Why it applies: category is "measured" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### indicated [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-12) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: resource - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:9f9ae0cdf98517b80bef - Deposit or zone: Total Xavantina Operations - Mining method: combined #### Resource Data - Category: indicated - Tonnes: 2047000 - Grade: 8.86 - Grade Unit: g/t - Contained Metal: 583.3 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The total Indicated Resource for Xavantina Operations shows a substantial, high-grade resource with good geological confidence, contributing significantly to the overall increase in M&I resources. - Positive factor: Indicated Resource category indicates good geological confidence. - Positive factor: Grade of 8.86 g/t Au is world-class for underground gold mining. - Positive factor: Significant contained metal of 583.3 koz Au. - Positive factor: Meaningful increases in overall measured and indicated resources. Evidence · table > 8.86 Context: 2,047 #### Tags used in scoring **Indicated Resource** Polarity: positive Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves. Why it applies: category is "indicated" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ### inferred [Link to this fact](https://atlas-extractions.minestarters.com/news/ero-announces-result-of-year-long-value-creation-initiative-at-xavantina-commenc--8d6e6ed5-e574-4da5-928f-10b384739ee2#fact-resource-facts-13) Xavantina Operations · gold #### Identity - Project: Xavantina Operations - Commodity: gold - Region: brazil - Reported Region: Mato Grosso State, Brazil - Ticker: ERO #### Resource scope - Estimate type: resource - Effective date: 2022-10-31T00:00:00.000Z - Reporting standards: ni\_43\_101 - QP Signed: Yes - Qualified person names: Mr. Cid Gonçalves Monteiro Filho - Resource group id: resource:c7860ca69deabde8a8a2 - Deposit or zone: Total Xavantina Operations - Mining method: combined #### Resource Data - Category: inferred - Tonnes: 1166000 - Grade: 9.75 - Grade Unit: g/t - Contained Metal: 365.4 - Contained Unit: koz - Cutoff Grade: 1.46 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2025-06-30 #### Lab - Laboratory: ALS Brasil Ltda., SGS Geosol - Laboratórios Ltda, ALS Peru S.A. #### Location - Loc. Confidence: medium #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2025-11-04T00:00:00.000Z Reasoning: The total Inferred Resource for Xavantina Operations shows high-grade potential but requires further drilling to upgrade its confidence category for economic studies. - Positive factor: Grade of 9.75 g/t Au is world-class for underground gold mining. - Negative factor: Inferred Resource category has lower geological confidence and cannot support economic studies alone. Evidence · table > 9.75 Context: 1,166 #### Tags used in scoring **Inferred Resource** Polarity: negative Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone. Why it applies: category is "inferred" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate ## How Atlas produces this analysis Minestarters Atlas uses automated extraction to summarize mining announcements, identify reported measurements, and classify supporting evidence. Sentiment reflects the extracted narrative and classification rules; it is an interpretation, not a reported measurement. Evidence quotes and context are provided where available. Missing data, low-confidence results, and review flags indicate limitations. Check the original publisher announcement before relying on an interpretation.