Solid silver calibration reference disc marked 830 (83% silver). Originally used as a standard sample for calibrating precious metal analyzers (e.g. XRF testing devices). Weight: 98.54 grams Silver content: 83% (830 fineness) Estimated pure silver weight: approx. 81.8 grams The piece shows normal signs of use and surface oxidation consistent with a working calibration sample. No deep scratches or damage affecting functionality. Ideal for jewelers, gold buyers, refineries, laboratories, or collectors of precious metal testing equipment. Will be carefully packed and shipped with tracking.