Video:What Is the Hardness Scale for Minerals?

Transcript:What Is the Hardness Scale for Minerals?

Hi I’m Geologist John Swanson and today I’m going to talk about the hardness scale for minerals.

Mineral Hardness is Measured on a Scale

In 1812, German mineralogist Frederich Mohs penned what would become what is referred to as Mohs’ Scale of Mineral Hardness. For his scale, he selected 10 minerals based upon their being common and readily available. It should be noted that the scale is not actually linear but rather arbitrary. Here is the Mohs Scale of hardness including the hardness number, the mineral associated and its common uses.

Mineral Hardness 1 – Talc

Associations and uses: talcum powder

Mineral Hardness 2 – Gymsum

Associations and uses: Plaster of paris. Gypsum is formed when seawater evaporates from the Earth’s surface.

Mineral Hardness 3 – Calcite

Associations and uses: Limestone and most shells contain calcite.

Mineral Hardness 4 – Fluorite

Associations and uses: Fluorine in fluorite prevents tooth decay.

Mineral Hardness 5 – Apatite

Associations and uses: used to manufacture fertilizer

Mineral Hardness 6 – Orthoclase

Associations and uses: Orthoclase is a feldspar

Mineral Hardness 7 – Quartz

Associations and uses: is a lovely crystal and is often used in jewelry

Mineral Hardness 8 – Topaz

Associations and uses: The November birthstone.

Mineral Hardness 9 – Corundum

Associations and uses: Sapphire and ruby are varieties of corundum.

Mineral Hardness 10 – Diamond

Associations and uses: Used in jewelry and cutting tools.

Hopefully now you understand the Mohs Scale of Hardness. Thanks for watching. If you’d like to learn more, please find us on the web at About.com.