|
 |
Items: 0 | Total: $0.00 |
|
|
 |
| 8.94ct VVS Sapphire |
| 4.26 x 3.35 x 1.89mm |
| $147.51 |
|
|
|
|
 |
| 2.87ct Sapphire |
| 9.4 x 7.34 x 4.15mm |
| $25.83 |
|
|
|
|
 |
| 1.29ct Sapphire |
| 7.77 x 5.76 x 2.99mm |
| $12.90 |
|
|
|
|
 |
| 5.7ct VVS Sapphire |
| 2.81 x 2.02mm |
| $56.43 |
|
|
|
|
 |
| 2.15ct SI Sapphire |
| 8.3 x 6.51 x 4.66mm |
| $154.80 |
|
|
|
|
 |
| 6.42ct VVS-VS Sapphire |
| 3.18 x 2.4mm |
| $80.89 |
|
|
|
|
 |
| 1.51ct VS Sapphire |
| 6.9 x 5.8 x 3.9mm |
| $56.60 |
|
|
|
|
 |
| 2.49ct Sapphire |
| 8.92 x 7.38 x 3.45mm |
| $22.41 |
|
|
|
|
|
| Mohs' scale of mineral hardness was created by the German mineralogist Friedrich Mohs in 1822 to measure the relative hardness or scratch resistance of various minerals. He based it on ten readily available minerals. As it is an ordinal scale, you have to compare two minerals to decide which is harder. The scale is neither linear nor logarithmic. For example, corundum is twice as hard as topaz, but diamond is almost four times as hard as corundum.
The hardness of a material is measured against the scale by finding the hardest material that that the given material can scratch, or the softest material that can scratch the given material. Mohs original scale is as follows:
|
Hardness |
Material |
Absolute Hardness |
1 |
Talc (Mg3Si4O10(OH)2) |
1 |
2 |
Gypsum (CaSO4·2H2O) |
3 |
3 |
Calcite (CaCO3) |
9 |
4 |
Fluorite (CaF2) |
21 |
5 |
Apatite (Ca5(PO4)3(OH-,Cl-,F-)) |
48 |
6 |
Orthoclase (KAlSi3O8) |
72 |
7 |
Quartz (SiO2) |
100 |
8 |
Topaz (Al2SiO4(OH-,F-)2) |
200 |
9 |
Corundum (Al2O3) |
400 |
10 |
Diamond (C) |
1500 |
|
To give some examples from everyday life,
a fingernail has a hardness of 2;
a copper penny, about 3;
a knife blade, 5;
window glass, 5.5;
and a steel file, 6.5.
Here are the Mohs scale ratings for various gemstones:
|
|
|
|
|
|
|
|
|
.gif){kind=small}