Steps to Identify rocks and minerals

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Steps to identify a rock or mineral

Do not use online apps. They rely on shape, color and light and can easily misidentify a rock or mineral.

After cleaning, give it a thorough inspection and take note of the following:

Color, uniformity and mix
Grain size- is it fine medium or coarse grained? Is it glassy? Waxy?
Texture- is it smooth, rough, bubbly or layered? Is it crystalline?
(not the texture as you feel it in your hands, but of the rock itself)
What do you see in the rock? Shapes or patterns? Fossils?

Classify its type-
Igneous? Metamorphic? Sedimentary?

Igneous rocks will have mostly fine grains with interlocking crystalline structures. they may have a bubbly appearance but rarely have any layers.

Metamorphic rocks tend to have bands/layers and look squashed in one direction so that all the layers are aligned. There may be recrystallization.

Sedimentary rocks can also have layers, but primarily there will be identifiable grains or even pebbles that are cemented together. They can hold fossils such as brachiopods and invertebrates, corals and more can also be found.


Test its hardness using the Moh’s scale where Diamond is the hardest at 10, and talcum powder is the softest at 1. This should be done in different areas but whatever the material is that its mostly composed of. This will tell you the mineral content.

Check the streak. using a streak plate. The powder color will also help to identify specific minerals and elements.

Any other special properties such as foaming under the acid test? Magnetism? What type of cleavage it has? Fracturing?

Once you have all this noted, compare your results with tables and charts found in books dealing with minerals.

If you still aren’t sure, then check with other club members.