Introduction
The Passione range is founded on a love for precious stones, and so this section of the site is intended to provide some information on the provenance and composition of the gems incorporated into the Passione pieces.
Mohs Scale
The Mohs scale is used to find a mineral's hardness.
It is based on the ability of a harder material to scratch a softer material. The hardness of a material is measured against the scale by finding the hardest material that the given material can scratch, and/or the softest material that can scratch the given material.
As the hardest known naturally occurring substance, diamond is at the top of the scale.
| Hardness | Mineral |
| 10 | Diamond (hardest) |
| 9 | Corundum |
| 8 | Topaz |
| 7 | Quartz |
| 6 | Feldspar |
| 5 | Apatite |
| 4 | Fluorite |
| 3 | Calcite |
| 2 | Gypsum |
| 1 | Talc (softest) |
Other materials fall into the scale thus:
| Hardness | Material |
| 2.5 | Fingernail |
| 2.5-3 | Gold, Silver |
| 3 | Copper penny |
| 4-4.5 | Platinum |
| 4-5 | Iron |
| 5.5 | Knife blade |
| 6-7 | Glass |
| 6.5 | Iron pyrite |
| 7+ | Hardened steel file |
Remember that the term "scale" is actually misleading. It should properly be referred to as a table, as the numbers are purely ordinal and not scalar. Diamonds are not ten times harder then talc, for example. The absolute hardness of the minerals in the Mohs scale are:
| Absolute hardness | Mineral |
| 1500 | Diamond (hardest) |
| 400 | Corundum |
| 200 | Topaz |
| 100 | Quartz |
| 72 | Feldspar |
| 48 | Apatite |
| 21 | Fluorite |
| 9 | Calcite |
| 2 | Gypsum |
| 1 | Talc (softest) |
