A shallow-formed silver deposit, usually carrying gold and base metals alongside.
A type of mineral deposit formed by hot, rising fluids in volcanic environments at shallow depths and low temperatures. Epithermal deposits are a major source of silver and gold, characterized by high-grade veins and stockwork mineralization.
These are the source of most primary silver production outside base-metal by-product. Grades are quoted in the hundreds of grams per tonne, which only looks extraordinary if you are comparing against gold.