If it is difficult to identify a mineral using physical characteristics then it may be necessary to undertake chemical analysis. This should be done by experienced scientists in a laboratory.

Different experiments can be performed to determine:-

(1) Soluability in Acids

Some minerals are almost completely insoluble e.g. gold.

Some are soluble in some materials but not in others e.g. copper dissolves in nitric acid only.

Biotite dissolves in sulphuric acid.

(2) Gases Produced

Sphalerite gives off a rotten egg smell when dissolved in hydrochloric acid, therefore indicating that it contains sulphur.

Some minerals may give off chlorine.

(3) Characteristics when placed in a Flame

By placing minerals in a flame it may be possible to identify them. Firstly, some may melt entirely e.g. pyrite and some will not melt at all e.g. sapphire.

Also different minerals give off different colour flames.

However, chemical analysis is not very useful as a method of identification for collectors because it damages or destroys the sample.