When you just start off exploring the wonders of minerals, working out mineral identification can seem a daunting task. It becomes a skill that you build over time – and mostly from experience of seeing lots and lots of minerals, and by asking others to help you ID your finds. Even after my own 35+ years in geology, I still ask friends to help me ID specimens for which I am not confident of my own answer.
Mineral Identification 101
Most people jump to the first and obvious mineral property to try and ID their find – color! But it is probably the least reliable property to use in mineral identification. Instead, you can follow some very simple tests to help identify that mineral in your hands.
And even if you can’t work it out, doing these tests and providing the information to a friendly mineral ‘expert’ will help them to help you!
Streak – take your mineral and scratch it against the back of a white ceramic tile. The mineral powder will have a color (often very different from the color of the mineral). What is the color?
Hardness – try and scratch the mineral with other items – a fingernail, copper coin, penknife…or even a known mineral – like quartz…and tell us what scratched what. For more about hardness, see here.
Cleavage/Fracture – does the mineral show any flat faces (cleavage or crystal faces)? How are they arranged? Are they at 90 degrees to each other or at an angle? What is the surface like where the mineral has been broken against those flat surfaces (fracture)?
Photos – If you want someone on the internet to help you ID, take some photos from different angles and in daylight. Others may be able to see crystal faces, cleavage or habit (the way the crystals grow)
Magnetic – If it is a metallic mineral…do all the above and then test it with a magnet and see if it is magnetic.
Providence – knowing where the mineral comes from can also help in its identification. This can be the locality (like ‘Mt Apatite”) or even “I found it in a vug with other minerals like mica”.
Once you have this basic information along with the color you should be able to work out most minerals or at least narrow it down to a few.
If you have geo-kids (young collectors..) you might like to check out the book I wrote to help them along the same process. Adults new to collecting also seem to enjoy it. You can see it on Amazon here.