Table of Contents
What do the numbers on the Mohs scale mean?
The scale by which the hardness of a mineral is determined as compared with a standard. The Mohs scale is a relative scale of hardness of ten standard minerals, higher numbers indicate the mineral can scratch minerals with a lower number, so calcite can scratch gypsum, but not fluorite.
What is an 8 on Mohs hardness scale?
In 1812, Friedrich Mohs – famous geologist and mineralogist created a scale of mineral hardness grading from the softest (1) to the hardest (10). The scale was created using the simple technique of one mineral’s ability to visibly scratch another….The Mohs Scale – A List of Gemstone Hardness.
| Gem | Hardness |
|---|---|
| Ruby | 9 |
| Sapphire | 9 |
| Chrysoberyl | 8.5 |
| Topaz | 8 |
How hard is obsidian on the Mohs scale?
Obsidian (/ˌɒbˈsɪdiən/; /əb-/) is a naturally occurring volcanic glass formed when lava extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock….
| Obsidian | |
|---|---|
| Fracture | Conchoidal |
| Mohs scale hardness | 5–6 |
| Luster | Vitreous |
| Specific gravity | c. 2.4 |
What is peridot on the Mohs scale?
about 6.5 to 7
It ranges from about 6.5 to 7 on Mohs hardness scale. Peridot is fairly dense with a specific gravity (weight of the crystal compared to the weight of an equal volume of water) ranging from about 3.27 to 3.37.
How did the Mohs hardness scale get its name?
This method is especially useful for identifying minerals in the field because you can test minerals against some very common objects (fingernail, a penny, a nail). The scale is named for its creator, the German geologist and mineralogist Friedrich Mohs.
What is the difference between Mohs hardness and Vickers hardness?
Mohs hardness is a resistance to being scratched, while Vickers hardness is a resistance to indentation under pressure. The graph shows the great difference between the Vickers hardness of corundum and diamond – which are only one unit apart on the Mohs hardness scale.
Which is harder diamond or apatite on Mohs scale?
This is because, while the numbers on the Mohs Scale moves up from 1 to 10 like a linear scale, it is in fact not a linear one. Meaning, Diamond at 10 is NOT twice as hard as Apatite at 5. Looking at the absolute hardness of these two minerals, Diamond is over 30 times harder than Apatite.
What is the hardness of dolomite on the Mohs scale?
For instance, dolomite, which scratches calcite but not fluorite, has a Mohs hardness of 3½ or 3.5. There are a few handy objects that also help in using this scale. A fingernail is 2½, a penny (actually, any current U.S. coin) is just under 3, a knife blade is 5½, glass is 5½ and a good steel file is 6½.