Sources or strategies for stone identification
Are your stones raw or are they cut &amp; polished as they would appear if mounted in jewellery pieces? There are tests such as streak &amp; hardness which can be done to raw stones but not to polished stones because these test would damage the polished surface.

There are a number of websites that can be used, such as:


Rock Identification Made Easy
Rocks: Igneous, Metamorphic and Sedimentary


Tests that should be done include:


Color
Luster
Hardness - usually involves testing with the blade of a pocket knife
or similar
Grain size - the size of mineral grains in the stones. If no mineral
grains are obvious the stone may be "glassy"
Streak - the color left on a piece of white ceramic when the stone is
rubbed on the ceramic.