How Do You Perform The Mohs Test?
How to Perform the Mohs Test Sunday July 22, 2007 One of my e-mails was a request for help identifying a rock. I’ll post more later about the rock, so you can help if you like. Identifying rocks and minerals relies heavily on chemistry, but most of us don’t carry around a chem lab when we’re outside, nor do we have one to take rocks back to when we come home. So… how do you identify rocks? You gather information about your treasure to narrow down the possibilities. It’s very helpful to know the hardness of your rock. There are several ways to define hardness. A metallurgist or engineer might use a different method from a geologist. Rock hounds often use the Mohs test to estimate the hardness of a sample. In this test, you scratch an unknown sample with a material of known hardness. Here’s how you can perform the test yourself: • Find a clean surface on the specimen to be tested. • Try to scratch this surface with the point of an object of known hardness, by pressing it firmly into an
