we have found tonnes of rock with faces of gold, some with tiny gold flecks others larger flecks shining and catching the light, sometimes the flecks appear to be fragments of copper, how do i find out what they really are?
2006-12-26 23:50:04 · 2 answers · asked by Katie 1 in Science & Mathematics ➔ Earth Sciences & Geology
Visible gold flakes in the rock ? That makes it a gold ore. Examine with a hand lens to check whether they are really gold or pyrite or some other sulphide mineral.
You can select a richer portion and crush the sample. Then pan it if u know how to pan. Otherwise take it straight to the nearest laboratory to analyse it. There is no short-cut method to identify gold by an untrained eye.
(I can suggest Mercury amalgamation, but it is too hazardous.)
However, if labs are not available to you or if their charges appear too high, you can try try dissolving the powdered sample in Aqua Regia (1:3 mixture of conc. nitric acid and conc hydrochloric acid). Gold will dissolve. Filter the acid, and let the filtered acid be evaporated. You can find the details of this procedure in the following website :
http://www.sas.org/E-Bulletin/2003-10-31/labNotes2/body.html
Exactly follow the steps they suggested.
But aqua regia fumes are also very very corrosive, so be extremely careful.
2006-12-27 04:32:36 · answer #1 · answered by saudipta c 5 · 0⤊ 0⤋
If it's shiney it's probably pyrite (fool's gold). To find out for sure take it to a university Geology department's Mineralogy expert.
2006-12-27 12:33:14 · answer #2 · answered by April C 3 · 0⤊ 0⤋