|
Developed
by Moh, a German mineralogist, this table is not a scale in
which the numbers indicate equal divisions of hardness. In
other words, the intervals of hardness between the numbers
are not equal. Moh’s Scale is valuable, when testing the
relative hardness of gem material, i.e., a mineral of
hardness 8 will scratch another mineral of hardness 7.
|
Relative
& Absolute Hardness Scale (Scratch Hardness :
Moh's)
|
Relative
Hardness can be evaluated with the following objects
|
| Talc |
1 |
Moh's
Hardness |
Can
be scratched with |
| Gypsum |
2 |
2.5
or under |
Finger
nail |
| Calcite |
3 |
3.0 |
Copper
coin |
| Fluorite |
4 |
6.0
to 7.0 |
Steel
file |
| Apatite,
Glass |
5 |
5.5
or under |
Knife
blade |
| Orthoclase |
6 |
5.5 |
Scratches
window glass |
| Quartz,
Amethyst |
7 |
|
|
| Topaz |
8 |
|
|
| Corundum,
Ruby, Sapphire |
9 |
|
|
| Diamond |
10 |
|
|
|
