Video:What Is the Hardness Scale for Minerals?with John Swanson
Mineral hardness is rated on a scale developed by mineralogist Frederich Mohs. Learn about the Mohs scale of mineral hardness in this educational geology video.See Transcript
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.