Here's how it works:
* Mohs Hardness Scale: This scale, developed by Friedrich Mohs in 1812, ranks minerals from 1 (softest) to 10 (hardest) based on their resistance to scratching.
* Scratch Test: A geologist will try to scratch an unknown mineral with a known mineral of a specific hardness. If the unknown mineral is scratched, it's softer than the known mineral. If the unknown mineral scratches the known mineral, it's harder.
* Example: A geologist might use a fingernail (hardness ~2.5) to try and scratch a mineral. If it scratches, the mineral is softer than a fingernail. If it doesn't, they might use a copper coin (hardness ~3.5) to try and scratch it, and so on.
By comparing the hardness of the unknown mineral to the known minerals on the Mohs scale, geologists can help identify the unknown mineral.
