I mention the Mohs scale each week in my Crystal posts but have never said what this scale is. Some of you may know, for those that don’t; here is the skinny on the Mohs Hardness scale. We can thank Friedrich Mohs, a German scientist and mineralogist for creating the hardness scale. Born in 1773 he showed an aptitude for the sciences form an early age, and in school studied Chemistry, Mathematics and Physics. After his schooling Mohs joined the Mining Academy to continue his studies with Abraham Werner.
In 1802 he moved to Austria where he had been hired to identify and catalogue a large mineral collection owned by a wealthy banker named J.F. van de Null. This collection would later be donated to a museum run by Mohs himself.
The process of identifying various crystal and minerals was completed visually and chemically. In his schooling Mohs knew that it was written in the writings of Pliny the Elder that some crystals and minerals are harder than others, meaning that they could be scratched by minerals harder than themselves. Taking this knowledge, he incorporated it into the identification process, and in time his Hardness Scale was born.
Knowing that Diamond is the hardest known substance, it was rated a 10. Talc the softest, and was rated a 1 on his scale. By process of trial the rest was filled in. Each category breaks down by halves, of course, because some crystals and minerals are harder than one level but not as hard as another. The system works though and is a great help to the field of geology. Especially working in the field to identify one mineral from another. The scale is as follows:
1 Talc
2 Gypsum
3 Calcite
4 Fluorite
5 Apatite
6 Feldspar
7 Quartz
8 Topaz
9 Ruby
10 Diamond
And with that we have the quick rundown on the Mohs Hardness scale. Have a fantastic day!
Blessed Be ❤ Sharon