| The Moh's Scale |
| The Moh's Scale was devised in the 19th century by German mineralogist, Fredrich Moh. He took 10 commonly available minerals, and classified them based on their hardness, or ability to be scratched by different minerals. The Moh's Scale is still used today to classify gemstones based on their hardness. Hardness Mineral 1 Talc 2 Gypsum 3 Calcite 4 Fluorite 5 Apatite 6 Orthoclase Feldspar 7 Quartz 8 Topaz, Emerald, Aquamarine 9 Corundum (Ruby & Sapphire - twice as hard as Topaz 10 Diamond (4 times as hard as Corundum) (The minerals listed above, are just an example of the ones in tat category.) The softest mineral is Talc, ( does Talcum Powder ring a bell? ), while the hardest is Diamond. So what does this mean in the real world? A mineral with the hardness of 7 will scratch any mineral of the same hardness or less, but can be scratched itself by a mineral with the same or higher number. Diamond, having the highest number, is the hardest gem known to man, and is used not only for beautiful jewelry, but also in many industrial applications, such as saws and drill bits, because of it's durability. The most valuable gems have a hardness of 7 or more. The most highly prized gemstones are also the hardest, like Diamond, Ruby, Sapphire and Emerald. Anything below a hardness of 7 is not viable for use in jewelry because everyday use would damage the stones. |