Quote Originally Posted by Florius Frammel View Post
Another possibility for a very simple pre-test to identify gold or silver would be to acertain the density. This is only sensible when having higher quantities of metals but a lot easier.

Weigh the object and note the mass.
Take a measuring cylinder and put in water (approx. half of the max. scale). Note the volume (V1).
Put your purefied metal sample into the cylinder and note the new volume (V2) as well.
Now first substract V1 from V2 (V2-V1) and note the result (V3).

Finally you can calculate the density by the formula

Density = mass/volume (in our case V3)

Density of gold: 19,3 g/cm3
Density of silver: 10,5 g/cm3

Note that the qualitative analysis described above can be more reliable as there are (few) metals that have similar densities (Tungsten: 19,25 g/cm3).
Further you should perform the volume measurements at room temperature.
Yes, that's another test that can be useful. But as you point out, you need more substantial amounts of the metal being tested. On the other hand, qualitative analysis can work even in milligram quantities.