Financing

The Mining and Exploration News in Mexico: Highlights on the Third Week of May, 2026

/ gambusinoprospectormexico / Leave a comment

Quartz Vein Displaying Boiling Texture

By Miguel A Heredia

During the 21st week of the year (May 18 to May 24, 2026), at least 31 press releases were issued by companies operating in Mexico, and 1 news published by the media. Of these, twelve related to deals and corporate matters, five addressed Mexican-related issues, four covered resource and development updates, three reported production results, three presented exploration results, three announced financing activities, and two discussing social issues.  ON MEXICO ISSUES, Almaden provided an update to the international arbitration proceedings under the Comprehensive and Progressive Agreement for Trans-Pacific Partnership with the United Mexican States. The Federal Mexican Government, through the Secretariat of Economy eliminates one procedure and simplifies 42 for mining investment. Sierra Madre received approval from the the Comisión Federal de Competencia Económica (COFECE) for the acquisition of the Del Toro Silver mine in Zacatecas. Mexican courts ruled that Capstone Copper owes unpaid royalties to Minera Portree de Zacatecas, S.A. de C.V (Royalties Inc) since 2019 on the Cozamin Mine, Zacatecas. Oroco and GR Silver reported the best drilling intercepts in Mexico on the third week of May, 2026. ON EXPLORATION, In Sonora, Masivo Silver informed that it completed its Phase 1 drill program at Cerro Colorado project, which consisted of seven holes totaling 1,601m, and JV Questcorp-Riverside reported that they have completed an expanded  aeromagnetic drone survey at the La Union project. ON MINING, IMPACT Silver and Sierra Madre reported Q1, 2026 operational and financial results. Starcore reported production and financial results for the four fiscal quarter ended April 2026. ON FINANCING, Vortex notified further extension of its previously announced non-brokered private placement. Sonoro Gold announced a non-brokered private placement for gross proceeds of CAD $10M. Kootenay informed that it intends to complete a non-brokered private placement for gross proceeds of up to CAD $500K. ON RESOURCES AND DEVELOPMENT, GR Silver released the best ever drill results at its San Marcial project in Sinaloa in hole SMS26-04, which intersected 45.1 m of 1,623 g/t Ag, Including 8.25 m of 8,579 g/t Ag,. Oroco reported drill results from its Santo Tomas project in Sinaloa. Silverco filed a NI 43-101 Technical Report for its Cusi mine, Chihuahua. Silver Storm released drill results from the C550 and C535 Zones within its Parrilla mine complex in Durango, and expands its 2026 drilling campaign by 9,000m.  ON DEALS AND CORPORATE ISSUES, Alamos Gold announced multiple management appointments, further strengthening its senior leadership team. Torex Gold announced the appointment of Dan Rollins as Chief Financial Officer. Minera Alamos has provided its notice of intent to exercise its option to repurchase a portion of the net smelter return royalty equal to 0.75% on the Cerro de Oro project located in northern Zacatecas. Vizsla appointed Dave D ´Antonio as Senior Vice President of Technical Services. Silver Spruce granted stock options to certain directors, officers, employees and consultants. Silverco completed its previously announced acquisition of Nuevo Silver Inc. Silver Tiger announced that the Toronto Stock Exchange has approved the listing of the Company’s common shares for trading on the TSX. Vizsla Silver appointed Guillermo Hernandez as Vice President Exploration and promotes Jesus Velador as Chief Geologist. GR Silver announced a celebration of Life for founder Márcio Fonseca. Silver Wolf announced adoption to semi-annual financial reporting. Americas Gold and Silver reached an agreement with Sprott Mining to terminate the remaining obligation under the existing Silver Delivering Agreement in exchange for shares of the company. GR Silver provided a corporate update following the exceptional drill results at San marcial within its Plomosas project, Sinaloa.  ON SOCIAL RESPONSIBILITY, Aura Minerals announced its 2025 Sustainability Report promoting safety, responsibility, sustainability, and innovation, prepared in with reference to Global Reporting Initiative standards. Heliostar published its inaugural Sustainability Report covering the 2025 fiscal year.

ON MEXICO ISSUES

  • Almaden Provides Update on Arbitration Process with Mexico Increased Damages Award Presented: Almaden Minerals Ltd
  • Federal Government Eliminates One Procedure and Simplifies 42 for Mining Investments:   Chihuahua al Día – Noticias
  • Mexican Courts Rule That Capstone Copper Owes Unpaid Royalties Since 2019 on the Cozamin Mine-Pending Amparo: Royalties Inc
  • Sierra Madre Receives Mexican Antitrust Approval for the Acquisition of the Del Toro Mine: Sierra Madre Gold and Silver Ltd
  • Oroco Resource Corp., and GR Silver Mining Ltd reported the best drilling intercepts in Mexico on the third week of May, 2026. Details are shown in the table below:

ON EXPLORATION  

ON MINING

ON FINANCING

ON RESOURCES AND DEVELOPMENT

  • GR Silver Reports Its Best Ever Drill Results at San Marcial: 45.1 m at 1,623 g/t Ag, Including 8.25 m at 8,579 g/t Ag, in Hole SMS26-04: GR Silver Mining Ltd
  • Oroco Intersects 228 m of 0.49% CuEq and 212 m of 0.44% CuEq at Santo Tomás: Oroco Resource Corp
  • Silverco Mining Files NI 43-101 Technical Report for the Cusi Project PEA: Silverco Mining Ltd
  • Silver Storm Demonstrates Resource Growth Potential at the C550 Zone, Expands the 2026 drilling campaign by 9,000m: Silver Storm Mining Ltd

ON DEALS AND CORPORATE ISSUES

ON SOCIAL RESPONSIBILITY

Content like what you have just read can be seen at https://gambusinoprospector.com/ and at LinkedIn’s Mexico Mineral Exploration Group.

On the picture below, a quartz vein displaying boiling texture in a project in Sonora, Mexico.  Photo taken by Miguel A Heredia.

The Mining and Exploration News in Mexico: Highlights on the First Week of May, 2026

/ gambusinoprospectormexico / Leave a comment

By Miguel A Heredia

During the 19th week of the year (May 4 to May 10, 2026), at least 27 press releases were issued by companies operating in Mexico. Of these, twelve related to deals and corporate matters, eight reported production results, three presented exploration results, two covered resource and development updates, one addressed Mexico-related issues, and one announced financing activities.  ON MEXICO ISSUES, Orla Mining announced steps it has taken to protect labour rights at its Camino Rojo mine in Zacatecas. ON EXPLORATION, In Sonora, Riverside reported high-grade gold, silver, and base metals assays from Phase 2 Field Work at La Union Project. In Durango, Pinnacle commenced an underground delineation drilling program at its El Potrero project, and Capitan Silver received final interpretative products and reports from its property-wide Airborne Magnetotelluric geophysical survey conducted at its Cruz de Plata project.  ON MINING, Aura, Endeavour, GoGold, Pan American Silver, Torex Gold, Gold Resource, and Gold Royalty reported Q1, 2026 financial and operational results. Discovery Silver announced that it will release its Q1, 2026 financial and operational results on May 14, 2026. ON FINANCING,  Silver Spruce announced extension of non-brokered private placement.  ON RESOURCES AND DEVELOPMENT, Luca Mining released assay results from its ongoing 2026 drilling program at the Tahuehueto mine in Durango. Sonoro announced that it will be completing a two-phased exploration campaign at its flagship Cerro Caliche project in Sonora, including 50,000m of RC drilling, as well as soil and rock sampling programs. ON DEALS AND CORPORATE ISSUES, Angel Wings has undertaken a strategic review of all of its properties, to identify a suitable joint venture partner for its prospective La Reyna project. Aura declared dividend of USD $0.78 per common share based on Q1, 2026 results. Heliostar announced the appointment of Dennis Wilson as Vice President, Health, Safety, Environment, and Sustainability, and Hernan Dorado as Vice President of Operations.  Orogen announced the appointment of Chad Wells to the Board of Directors. Silver Viper completed acquisition of Coneto project, Durango. Orex completed sale of Coneto project, Durango to Silver Viper. Silver Spruce announced Change to Director Slate for its annual general and special meeting of shareholders and reported voting results. Pan America Silver and Torex Gold announced an enhanced shareholder return in 2026 through a combination of dividends and common share repurchases, including capital return. Capitan Silver reported voting results from its annual general and special meeting of shareholders, and adopted a shareholder rights plan and a 10% fixed omnibus equity incentive plan.  Radius Gold announced the adoption of semi-annual financial reporting. ON SOCIAL RESPONSIBILITY, No relevant news.

ON MEXICO ISSUES

  • Orla Mining Takes Action to Protect Labour Rights at Camino Rojo: Orla Mining Ltd

ON EXPLORATION

  • Riverside Resources Reports High-Grade Gold, Silver and Base Metal Assays from Phase 2 Field Work at La Union Project: Riverside Resources Inc
  • Pinnacle Commences Underground Delineation Drilling Program at El Potrero: Pinnacle Silver And Gold Corp
  • Capitan Silver Receives Final Results from Airborne Geophysics Program for the Cruz De Plata Project: Capitan Silver Corp.

ON MINING

ON FINANCING

ON RESOURCES AND DEVELOPMENT

  • Luca Intersects 6.8 Metres of 5.5 g/t Gold Equivalent at Tahuehueto Mine – Further Expanding High-Grade Mineralization Proximal to Existing Workings: Luca Mining Corp
  • Sonoro Gold Commences 50,000 meter Drilling Program: Sonoro Gold Corp

ON DEALS AND CORPORATE ISSUES

  • Angel Wing Sells Ontario Quartz Lake Claims to Kenorland, Advances Corporate Strategy: Angel Wing Metals Inc
  • Aura Declares Dividend of US$0.78 Per Share and US$0.26 Per BDR Based on Q1 2026 Results, Resulting in a Dividend Yield of 4.5% in the LTM: Aura Minerals Inc
  • Heliostar Announces Addition to Management Team and Ana Paula Focused Reorganization: Heliostar Metals Ltd
  • Orogen Royalties Appoints Mr. Chad Wells to the Board of Directors: Orogen Royalties Inc
  • Silver Viper Minerals Completes Sale of the Coneto Silver-Gold Project: Silver Viper Minerals Corp
  • Orex Minerals Inc. Completes Sale of Coneto Silver-Gold Project to Silver Viper Minerals: Orex Minerals Inc
  • Silver Spruce Resources Inc. Announces  Change to Director Slate for Annual General and Special Meeting of Shareholders: Silver Spruce Resources Inc
  • Silver Spruce Resources Inc. Announces Results of Annual and Special Meeting of Shareholders: Silver Spruce Resources Inc
  • Pan American Silver Targets Up to $1 Billion in Shareholder Returns in 2026 Through Enhanced Shareholder Return Framework: Pan American Silver Corp
  • Torex Gold Reports Enhanced Return of Capital Program: Torex Gold Resources Inc
  • Capitan Silver Announces Annual General and Special Meeting and Adoption of Omnibus Equity Incentive Plan and Shareholder Rights Plan: Capitan Silver Corp
  • Radius Gold Adopts Semi-Annual Financial Reporting: Radius Gold Inc

ON SOCIAL RESPONSIBILITY

  • No relevant news.

Content like what you have just read can be seen at https://gambusinoprospector.com/ and at LinkedIn’s Mexico Mineral Exploration Group.

On the picture below, a rhyolite flow of the Upper Volcanic Supergroup of the Sierra Madre Occidental in Chihuahua, Mexico.  Photo taken by Miguel A Heredia.

The Mining and Exploration News in Mexico; Highlights on the Fifth Week of April 2026

/ Gambusino Prospector / Leave a comment

By Jorge Cirett

During the 18th week of the year (April 27th to May 3rd, 2026), companies working in Mexico released 26 press releases. One company informed on early-stage property work, nine companies presented quarterly and/or full-year reports. One company updated on a financing round, two more are to trade on additional markets and one informed on its reporting policies. Two companies released drill results on their advanced project/mine, one more presented a MRE and another one contracted mineral estimation services. One company signed a definitive agreement on an acquisition, two companies announced their AGM’s results, one a management update and one more the election of directors. ON MEXICO ISSUES, several mining unions made clear their repulsion to the law amendments that severely restricted their participations on companies’ earnings. ON EXPLORATION, in Sinaloa, Mercado Minerals released drilling results on Copalito.  ON MINING, Gold Royalty, Orogen Royalties, Guanajuato Silver, Sierra Madre Gold and Silver, Capstone Copper, Alamos Gold, Agnico Eagle, Americas Gold and Silver and Minera Alamos reported quarterly and/or yearly results. ON FINANCING, Sonoro Gold closed a C$12.2 M private placement. Pinnacle Silver and Gold and Silver Viper started trading on different markets. Silver Spruce announced its reporting policies. ON RESOURCES AND DEVELOPMENT, Silver Storm released drilling results from La Parrilla, in Durango. Guanajuato silver filed the MRE on Bolañitos, Guanajuato. Luca Mining presented assays from drilling at Campo Morado, in Guerrero. Aztec Minerals engaged a service company to elaborate the MRE on Cervantes, Sonora. ON DEALS AND CORPORATE ISSUES, Silverco Mining executed the definitive agreement to acquire Nuevo Silver (La Negra, Querétaro). Chesapeake Gold is now a member of the Mining Association of Canada. Pan Amnerican Silver and Capstone Copper announced theirs AGM’s results. Agnico Eagle announced the election of directors. ON SOCIAL RESPONSIBILITY, First Majestic Silver announced its 2025 sustainability report.

ON MEXICO ISSUES

ON EXPLORATION

  • Mercado Minerals Intersects 6.50 Metres of 256 g/t Silver and 1.46 g/t Gold from 43.60 m Depth at 5 Senores Vein Copalito Project: Mercado Minerals (Copalito, Sinaloa)

ON MINING

  • Gold Royalty Announces Record First Quarter 2026 Preliminary Results: Gold Royalty    (Cozamin, Zacatecas)
  • Orogen Royalties Reports Record Revenue and Strong Earnings Growth in 2025: Orogen Royalties (royalty on Ermitaño, Sonora)
  • Guanajuato Silver Announces Year-End and Q4 2025 Results: Guanajuato Silver
  • Sierra Madre Reports Q4 and Year-End 2025 Financial Results, Positive Operating Performance: Sierra Madre Gold and Silver (La Guitarra, Estado de México) The company sold 271.2 K Oz Ag, 4,041 Oz Au, or 628.2 K Oz AgEq during 2025.
  • Capstone Copper Reports First Quarter 2026 Results: Capstone Copper (Cozamin, Zacatecas). The company produced 5,930 tonnes Cu at cash cost $0.71 per Lb Cu at Cozamin.  
  • Alamos Gold Reports First Quarter 2026 Results: Alamos Gold (Mulatos, Sonora). The company produced 32,700 Oz Au at cash cost $971 per Oz Au and mine-AISC of $995 per Oz Au at the Mulatos district.
  • Agnico Eagle Reports First Quarter 2026 Results, Including Record Quarterly Operating Margins and Adjusted Net Income: Agnico Eagle Mines (Pinos Altos, Chihuahua)
  • Americas Gold and Silver Provides Notice of First Quarter 2026 Results and Conference Call: Americas Gold and Silver (Cosalá, Sinaloa)
  • Minera Alamos Reports Fourth Quarter and Full Year 2025 Results; Record Quarterly Revenue of C$43.6 Million and Record Earnings from Mine Operations of C$20.1 Million: Minera Alamos (Santana, Sonora)

ON FINANCING

  • Sonoro Gold Announces Closing of Oversubscribed $12.2 Private Placement: Sonoro Gold  (Cerro Caliche, Sonora)
  • Pinnacle Commences Trading on OTCQB: Pinnacle Silver and Gold (Potrero, Durango)
  • Silver Spruce Resources Inc. Announces Adoption of Quarterly Reporting Exemption Under Coordinated Blanket Order 51-933: Silver Spruce Resources (Pino de Plata, Chihuahua)
  • Silver Viper Minerals Upgrades to OTCQX Best Market: Silver Viper Minerals (La Virginia, Sonora)

ON RESOURCES AND DEVELOPMENT

  • Silver Storm Drills 473 g/t Ag.Eq Over 3.6 m and 137 g/t Ag.Eq Over 12.0 m, Extends the San Nicolás Zone at Depth: Silver Storm. (La Parrilla, Durango)
  • Guanajuato Silver Files Technical Report for Bolañitos Mine: Guanajuato Silver (Bolañitos, Guanajuato) The deposit contains 22.2 M Oz AgEq, in all categories
  • Luca intersects 118 Metres of 2.5 g/t Gold, 78.0 g/t Silver, 0.8% Copper, 0.6% Pb and 2.0% Zinc at Largo Norte Zone, Campo Morado Mine: Luca Mining (Campo Morado, Guerrero)
  • Aztec Minerals Engages APEX Geoscience Ltd. to Commence Maiden Mineral Resource Estimates on the Tombstone and Cervantes Projects: Aztec Minerals (Cervantes, Sonora)

ON DEALS AND CORPORATE ISSUES

  • Silverco Mining Executes Definitive Agreement for the Acquisition of Nuevo Silver: Silverco Mining: (Cusi, Chihuahua; La Negra, Querétaro)
  • Chesapeake Announces Membership in the Mining Association of Canada; Management Update: Chesapeake Gold (Metates, Durango)  
  • Pan American Silver Announces Results of Annual General and Special Meeting: Pan American Silver (La Colorada, Zacatecas)
  • Capstone Copper Announces 2026 Annual General Meeting Results: Capstone Copper (Cozamin, Zacatecas)
  • Agnico Eagle Announces Election of Directors: Agnico Eagle Mines

ON SOCIAL RESPONSIBILITY

  • First Majestic Announces 2025 Sustainability Report and Mailing of 2026 AGM Meeting Materials: First Majestic Silver  (Santa Elena, Sonora)

On the image below: Epithermal quartz veining and pyrite in volcanosedimentary rocks, HQ core. Picture by Jorge Cirett.

The Mining and Exploration News in Mexico: Highlights on the Fourth Week of April, 2026

/ gambusinoprospectormexico / Leave a comment

Fe-Magnetite Skarn

By Miguel A Heredia

During the 17th week of the year (April 20 to April 26, 2026), at least 25 press releases were issued by companies operating in Mexico. Of these, ten related to deals and corporate matters, six covered resource and development updates, four reported production results, three presented exploration results, one addressed Mexico-related issues, and one announced financing activities. ON MEXICO ISSUES, Heliostar, IMPACT Silver, and GR Silver reported the best drilling intercepts in Mexico on the fourth week of April, 2026. ON EXPLORATION, In Sonora, Zacatecas Silver completed surface mapping and sampling at its Oso Negro project. In Chihuahua, Kingsmen commenced drilling at its Las Coloradas project in the Parral. In Durango, Pinnacle announced that it has discovered more high-grade polymetallic mineralization at its Potrero project.  ON MINING, Altius expected to report Q1, 2026 expected attributable royalty revenue of approximately CAD $26.4M. Pan American Silver announced that it will release the Q1, 2025 production results on may 5, 2026, and informed that it will hold its Annual General and Special Meeting of Shareholders on April 30, 2026. Avino reported Q1, 2026 production results of 263K Oz Ag, 1,851 Oz Au, and 1.34M Lb Cu for a total of 568.1K Oz AgEq. Sailfish reported Q4, 2025 operating and financial results.  ON FINANCING,  Coeur completed a private exchange offer to replace nearly $385.8M, (about 96.45%) of its outstanding 6.875% Senior Notes due 2032 issued by New Gold Inc. with new 6.875% Senior Notes and cash.   ON RESOURCES AND DEVELOPMENT, IMPACT Silver released new drill results on the Carlos Pacheco Vein System at its producing mine Noche Buena in the Royal Mines of Zacualpan District, State of Mexico. Oroco provided an update on its ongoing Phase 2 drill program at its Santo Tomas project in Sinaloa. Silver Dollar commenced drilling at its la Joya project in Durango.  Starcore initiated a airborne geophysical survey over its San Martin mining concession in Queretaro. Chesapeake received a US patent for its proprietary method of enhanced metal recovery from sulphide ores. GR Silver released results from drill holes SM SMS26-01 and SMS26-03 in the SE Area of San Marcial that confirm the continuity of high-grade silver mineralization up to 500m down dip from surface. Heliostar announced additional results from the ongoing drill program at its 100% owned Ana Paula project in Guerrero, reporting 69.15m grading 10.1 g/t in the High Grade Panel. ON DEALS AND CORPORATE ISSUES, Silver Dollar announced that it has agreed to extend its October 15, 2025 advertising and investor awareness marketing agreement with Dig Media Inc. Vizsla awarded the Engineering, Procurement and Construction Management contract to M3 Engineering & Technology Corp., and entered into a Mine Design contract with Mining Plus. VVC granted stock options to officers, directors, and consultants to purchase up to an aggregate of 14,750,000 common shares. Teck declared dividend of CADS $0.125 per share, to be paid on June 30, 2026 to shareholders of record at the close of business on June 15, 2026. Colibri announced adoption of semi-annual financial reporting. Royalties Inc granted stock options to directors, officers, consultants, and service providers. Teck reported voting results from its Annual Meeting of Shareholders.  Pantera Silver announced adoption of semi-annual financial reporting. Silverco announced filing of 2025 audited financial statement and MD&A.   ON SOCIAL RESPONSIBILITY, No relevant news.

ON MEXICO ISSUES

  • Heliostar Metals Ltd, IMPACT Silver Corp., and GR Silver Mining Ltd reported the best drilling intercepts in Mexico on the fourth week of April, 2026. Details are shown in the table below:

ON EXPLORATION

  • Zacatecas Silver Completes Surface Sampling and Mapping Program at Oso Negro Project, Sonora, Mexico: Zacatecas Silver Corp
  • Kingsmen Commences drilling at its Las Coloradas Silver-Gold Project Parral Mining District, Chihuahua, Mexico: Kingsmen Resources Ltd
  • Pinnacle Discovers More High-Grade Polymetallic Mineralization at El Potrero with Silver Assays up to 1,159 grams per tonne Underscoring District Scale Potential: Pinnacle Silver and Gold Corp

ON MINING

ON FINANCING

  • Coeur Mining, Inc. Announces Expiration and Final Results of Previously Announced Exchange Offer and Consent Solicitation for New Gold Senior Notes: Coeur Mining Inc

ON RESOURCES AND DEVELOPMENT

  • IMPACT Silver Intersects 114.5 g/t Gold, 1,295g/t Silver and 1.10% Copper over 0.61m Within9.79 g/t Gold, 212 g/t Silver and 0.29% Copper over 9.49m on Carlos Pacheco Vein Extension at Noche Buena Mine: IMPACT Silver Corp
  • Oroco Increases Activity at Santo Tomas: Oroco Resource Corp
  • Exploration Drilling Underway at Silver Dollar’s La Joya Silver (Copper-Gold) Project:   Silver Dollar Resources Inc
  • Starcore Announces Airborne Mobile MT Geophysical Survey  at San Martin Mine, Queretaro, Mexico: Starcore International Mines Ltd
  • GR Silver Reports High-Grade Silver Results from the 20,000 m Step-Out Drilling Campaign at San Marcial: 15.6 m at 351 g/t Ag, including 2.5 m at 1,395 g/t Ag, in SMS26-03: GR Silver Mining Ltd
  • Heliostar Drills 69 Metres Grading 10.1 g/t Gold in the High Grade Panel at Ana Paula: Heliostar Metals Ltd

ON DEALS AND CORPORATE ISSUES

  • Silver Dollar Extends Advertising and Investor Awareness Campaign with Investing News Network: Silver Dollar Resources Inc
  • Chesapeake Gold Receives a U.S. Patent for Enhanced Metal Recovery from Sulphide Ores: Chesapeake Gold Corp
  • Vizsla Silver Awards EPMC and Mine Design Contracts for the Development of the Panuco Silver-Gold Project: IZSLA SILVER AWARDS EPCM AND MINE DESIGN CONTRACTS FORTHE DEVELOPMENT OF THE PANUCO SILVER-GOLD PROJECT: Vizsla Silver Corp  
  • VVC Grants Options: VVC Exploration Corporation
  • Colibri Resource Corporation Announces Adoption of Quarterly Reporting Exemption Under Coordinated Blanket Order 51-933: Colibri Resource Corporation
  • Royalties Inc. Grants Stock Options: Royalties Inc
  • Teck Reports Voting Results from Annual Meeting of Shareholders: Teck Resources Limited
  • Pantera Silver Corp. Announces Adoption of Semi-Annual Financial Reporting: Pantera Silver Corp
  • Silverco Mining Announces Filing of 2025 Audited Financial Statement and MD&A: Silverco Mining Ltd

ON SOCIAL RESPONSIBILITY

  • No relevant news.

Content like what you have just read can be seen at https://gambusinoprospector.com/ and at LinkedIn’s Mexico Mineral Exploration Group.

On the picture below, Fe-magnetite skarn in a Cu-Au bearing skarn system in Hidalgo, Mexico.  Photo taken by Miguel A Heredia.