The Mohs Hardness Scale is a standard that indicates the hardness of minerals. It was first proposed by German mineralogist Frederich Mohs in 1822.
) The duality or state of being obdurate; invincible hardness of heart; obstinacy. Obdurate (a.) Hardened in feelings, esp. against moral or mollifying influences; unyielding; hard-hearted; stubbornly wicked. Obdurate (a.) Hard; harsh; rugged; rough; intractable. Obdurate (v. t.) To ...
Obsidianis a naturally occurring volcanic glass. It is formed during the eruption of felsic lavas, which are distinguished by having high concentrations of the chemical element silica. Because of their high silica content, felsic lavas do not behave like the mafic, or silica-poor, lavas we see ...
Mohs Hardness Scale is a set of reference minerals used for classroom hardness testing. Determining the hardness of a mineral is one of the most important tests used in mineral identification. The best way to learn about minerals is to study with a collection of small specimens that you can ...
I could test the hardness and other properties of obsidian, which was actually my favorite piece in the set. It was so shiny, yet it was so smooth and didn’t contain any glittery crystals at all. I worked with the other stones as well, but my eye was always drawn back to the obsid...
The kit came with a booklet that showed how to identify minerals by their hardness and luster. I could do scratch tests to determine a mineral's position on the hardness scale, and all I had to do was look at it closely to see the level of luster. ...