VPRS 19304 Laboratory Register of Assays

This series contains the laboratory reports of assaying undertaken by the laboratories of Geological Survey Victoria (VA 4118) and the Mines Department (VA 612).  An assay is a chemical analysis used to determine the proportion of metallic (gold, silver, copper, etc.) or non- metallic (sulphur, phosphorus, etc.) elements in a sample. It is also used to determine the quality and purity of the ore or precious metal and identify pollutants or impurities. Geological samples were collected by individuals, businesses, or government departments from sites across Victoria, and included brown and black coal, quartz, tailings, bore water, mine air, rock, silt, and clay. Each half-page laboratory report is presented in a standardised printed form, which was filled in with the handwritten remarks of the chemist completing the assay treatment. Each entry records the assay number, the date of assay at the laboratory, the character and description of the sample, the chemical test applied (called treatment), and the results (usually the amounts of gold, silver or other ores found in the sample). The entries are then signed and dated by the chemist. The level of detail in each report varies through the years and the reports become particularly sparse with the commencement of separately maintained assay reports (VPRS 19143 Assay Reports).