Examples from the Web for sylvanite
A small part of the world's supply is obtained from the gold-silver tellurides—calaverite, sylvanite, krennerite, and petzite.The Economic Aspect of Geology|C. K. Leith
He 'lows it's sylvanite, same as they have over to Boulder County in Colorado.
He figgers this sylvanite lies under this porphyry reef, sabe?
This side the exposed reef may have been ground down below the sylvanite.
But the strikes were rich because sylvanite is one of the richest of all gold ores.