Name of the Mine
Sunshine mine.

Location  
Silver Valley, in Idaho, in the US.

Mine Owner/s  
Sunshine Silver Mining & Refining Company (SSMRC), 71%-owned by Electrum Group.

Brief Description  
The Sunshine mine complex is home to North America’s highest-grade large silver resource and its only fully integrated silver operation, combining the Sunshine mine and the Sunshine refinery.

The mining complex is uniquely permitted to refine critical minerals essential to US national security and high-tech industries – antimony, gallium and germanium.

Brief History  
SSMRC acquired the Sunshine mine in 2010 and has since expanded resources, increasing the land package, modernising infrastructure, and laying the groundwork for the Sunshine complex to re-emerge as North America’s premier silver and critical minerals hub. 

Primary Metals/Minerals  
Silver.

Secondary Metals/Minerals  
Antimony, gallium and germanium.

Geology/Mineralisation  
The Coeur d’Alene mining district, including Sunshine, hosts silver/lead/zinc mesothermal vein deposits that are contained in Precambrian (about 1.45-billion years old) metasedimentary rocks of the Belt Supergroup. The Sunshine mine is predominantly hosted in the St Regis Formation, which is more than 183 m thick, and upper strata of the underlying Revett Formation. Rock types in the St Regis Formation are mainly argillite and siltite, which grade to siltite and quartzite in the Revett Formation. Both host units are intensely folded and faulted and metamorphosed to low-grade, greenschist facies. Dominant veins in the mine strike generally east-to-west between the faults and dip steeply (more than 60 ° to the south). More than 35 veins have been named and mined at the Sunshine mine. Historically, mined grades are exceptionally high in some areas, with averages of more than 100 troy ounces per short ton of silver. Mineralisation comprises tetrahedrite, galena and sphalerite, with typical gangue minerals of siderite, quartz, pyrite and magnetite.

Reserves  
Not stated.

Resources  
The Sunshine mine hosts an indicated resource of 3.3-million tonnes grading 1 067 g/t silver containing 112-million ounces, with 165-million ounces in inferred resources, SSMRC reported in October 2025.

Type of Mine
Underground.

Mining Method  
Detailed work has not been conducted, owing to the current project stage. However, for conceptual purposes and to estimate a cutoff grade, mining is assumed to be a mechanised, selective, underground method.

Major Infrastructure/Equipment  
Critical systems are in place in anticipation of the restart of the mine – shafts, hoists, substations, water pumping stations and a fully integrated power grid – alongside 8 km of underground rail, air, water and communications infrastructure. 

Prospects  
SSMRC aims to deliver a feasibility study for a silver/antimony mining and refining operation at the Sunshine mine in 2027, which will possibly also include the ability to produce gallium and germanium.

Contact Details 
Sunshine Silver Mining & Refining
Tel +1 208 783 1700 
Email info@silveropp.com
Website https://sunshinesilvermining.com/