2021-7-7 · 30 years experience. Hard rock, black sands, cons, native, sulfides, tellurides. $35 Au + Ag assay, $30 Au only. $10 prep per sample if needed (jaw, dry, split, pulverize to the consistency of coarse flour, about 40 mesh) Please send 60-100 grams of material that best represents your ore. Please note: I do only Au and Ag.