FrugalRefiner said:
Aeon13 said:
I learned that tungsten has a close SG with gold, Is that what you mean by "creative alloying"? I buy gold from miners that I know only and alloying of different metals is one subject they don'e know. But assuming I have a legit gold with 17.3 g/cm3 specific gravity will my calculation work and is it safe to say or estimate that it has 89.637% pure gold?
No. As 4metals mentioned, and as you seem to have some understanding, it depends on what metals are mixed with the gold. Consider the difference in specific gravity between aluminum and lead. If you add equal amounts of each to the same quantities of gold, the specific gravity of the two samples will be quite different, even though the amount of gold in each sample will be the same.
You have to know what metals are mixed with the gold to be able to calculate the gold percentage from specific gravity. In your example, you're ignoring the specific gravity of anything but the gold.
I'm gonna get convoluted and quite possibly wrong here:
If I'm not wrong, your math (SG of sample/SG of gold) determines the percent of gold only if your only other "contaminant" has a specific gravity of 0. What I'm thinking is something like (SG
Sample-SG
base)/(SG
Au-SG
base) would tell you how close your sample is to gold, given the difference between the densities of gold and the base metal present. So if the only other possible metal was copper (SG=8.94), you'd get a final result of (17.3-8.94)/(19.3-8.94)=80.7%. But if your only other metal is aluminum (SG=2.71), your sample is 87.9% gold.
But that doesn't really work either. For it to work, you'd have to know the total density of everything else in the mix, given their concentrations. And if I recall correctly, alloys don't always average their densities. In other words, a 50/50 alloy of two metals does not necessarily have a density halfway between the two base constituents.
Fire assay?