This item is 1 troy ounce (31.1 grams) of Argentium casting grain. Argentium is a special jeweler's silver alloy that is brighter and whiter than typical silver, and more tarnish-resistant. This is Argentium 960, which is a higher grade than sterling silver (96% silver vs. 94%). Originally bought from Gallatin & Socha Metals, this is great for casting high-quality silver jewelry!