Mohs Scale of Hardness April 17 2013, 0 Comments

This blog post is dedicated to Mohs scale of hardness. We use it frequently with our stone of the month series so we wanted to take this opportunity to dedicate an entire post to explain it. It is important to know the Mohs hardness in order to better care for different gemstones.

The Mohs scale is a way of measuring a stone's scratch resistance against a harder material. It was invented in 1812 by the German geologist and mineralogist Friedrich Mohs and ever since has been used to test and describe the hardness of minerals. While Mohs was the first one to invent an actual scale, testing the hardness of minerals by scratching them against each other was nothing new to people at that point. As a matter of fact, people had been doing it for hundreds of years prior.

Mohs Scale of Hardness, from gia.edu

 

The scale goes from 1 being the softest to 10 the hardest. If you have been following our birthstone blog series, then you know that diamonds are the hardest of all minerals, measuring a 10 on the Mohs scale of hardness. The turquoise on the other hand only measures a 5-7 on the Mohs scale of hardness, which makes this stone soft and prone to scratches. To give you a better idea of how hard a diamond actually is let's compare it to common objects. For example a fingernail is a 2.5 on the scale, while a copper penny is not much higher with a 3 on the Mohs scale of hardness. Glass on the other hand is already about a 7 on the Mohs scale of hardness, making it about as hard as quartz. I hope this helped you understand what we are talking about when we get a little bit carried away with all of our jewelry and gemstone talk!