A miner earning the majority of its revenue from silver rather than as a credit.
A mining company where silver is the principal metal produced and accounts for the majority of revenue, as opposed to companies producing silver as a by-product of gold, copper, or lead-zinc operations.
There are very few of them, which is why investors seeking silver exposure often end up holding base metal risk instead. A genuine primary silver producer offers leverage to the silver price that a by-product miner does not.