Yuan Lei's Little Knowledge | Mohs Hardness of Powder

Release time:

2024-01-29 09:34

Mohs hardness

Mohs hardness is a standard of mineral hardness, also known as Mohs hardness. It was first proposed by German mineralogist Frederick Morse in 1822. is a standard used in mineralogy or gemology.

Mohs hardness is scratched by a pyramidal diamond needle on the surface of the mineral under test using the scratch method, which is customarily used in mineralogy or gemology.

The hardness is expressed by measuring the depth of the scratch in ten grades (scoring method):Talc 1 (minimum hardness), gypsum 2, calcite 3, fluorite 4, apatite 5, orthostatite 6, quartz 7, topaz 8, corundum 9, diamond 10.The hardness of the measured mineral is determined by comparison with the standard mineral in the Mohs hardness tester. Although the measured value of this method is rough, it is convenient and practical. Commonly used to determine the hardness of natural minerals.

The hardness value is not an absolute hardness value, but a value expressed in order of hardness.


Standard data


Hardness, hardness, mineral, standard, scratch, said, mineralogy, scoring, gemstones

Different applications and specifications of washed kaolin and calcined kaolin


Kaolin is a non-metallic mineral, which is a kind of clay and clay rock mainly composed of kaolinite clay minerals. Because it is white and delicate, also known as white earth. It is named after Gaoling Village, Jingdezhen, Jiangxi Province.

Source Lei gas barium sulfate ten uses


Barium sulfate is based on barite as the main raw material, through beneficiation, ore washing, crushing and other processes. Barium sulfate has a hardness of 3~3.5 (Mohs) and a specific gravity of 4.3~4.7. It has the characteristics of high specific gravity, low hardness and brittleness. Barite is almost insoluble in water, ethanol and acid, soluble in hot concentrated sulfuric acid. With the development of some high-performance barium sulfate products, the application field of barium sulfate is constantly expanding.