Identifying Gold Minerals

There is no simple blowpipe or chemical test for gold. Ordinarily its physical characteristic are sufficient to identify it. 

Easily fusible at 2.5-3, Insoluble in ordinary acids but soluble in a mixture of hydrochloric and nitric acids. To be distinguished form certain yellow sulfides (particularly pyrite and chalcopyrite) and from yellow flakes of altered micas by its malleability, its insolubility and its great weight.

Occurrence. Although gold is a rare element, it is to be found widely distributed in nature, occurring small amounts. Its presence as a primary constituent of igneous rocks, more particularly of commonly in quartz veins. It occurs in detrital sands and gravels in what are known as placer deposits. It present in small amounts in sea water. Is it important to note that gold occurs almost wholly as the native metal, the only class of compounds which it forms in nature being the tellurides.