Testing
Gold Final Assays, Safekeeping
We perform gold final assays for buyers at local refineries to determine purity and fineness. We have various types of assays depending on clients preferences ; dry assaying method i.e. by fusing the powdered ore with or without fluxes and wet assaying method i.e. by the agency of liquids.
Fire Assays
Fire assay is considered the most reliable method for accurately determining the content of gold in ores or concentrates. This process involves melting a gold-bearing sample in a clay crucible with a mixture of fluxes (like silica and borax), lead oxide (called litharge), and a reducing agent (frequently flour).
Purity
In the jewelry industry, gold content is specified by karat. Pure gold is designated 24 karats; therefore, each karat is equal to 4.167 % gold content, so that, for example, 18 karats equal 18 × 4.167, or 75 % gold. “Fineness” refers to parts per thousand of gold in an alloy; e.g., three-nines fine would correspond to gold of 99.99 % purity.
