|
...
|
Ranking
|
Mineral
|
Natural form
|
Form
of usage
|
|
Softest
|
1
|
Talc
|
...
|
...
|
|
...
|
2
|
Gypsum
|
...
|
...
|
|
...
|
3
|
Calcite
|
 |
...
|
|
...
|
4
|
Fluorite
|
...
|
...
|
|
...
|
5
|
Apatite
|
...
|
...
|
|
...
|
6
|
Feldspar
|
...
|
...
|
|
...
|
7
|
Quartz
|
...
|
...
|
|
...
|
8
|
Topaz
|
...
|
...
|
|
...
|
9
|
Corundum
|
...
|
...
|
|
Hardest
|
10
|
Diamond
|
...
|
...
|
©1999,
2000 by the Regents of the University of California.
All rights reserved.
All rights reserved.