What is The Mohs Hardness Scale?
Wholesale gas prices in the Netherlands and the UK have risen 20 percent recently amid concerns about Russian supplies.
The EU plans to cut its dependence on Russian gas by two-thirds this year and stop importing Russian fossil fuels by 2027. Russia exported about 155 billion cubic meters of gas to the EU in 2021.
The US recently said it would try to supply 15bn cubic meters of LNG to the EU this year. U.S. LNG plants are running at full capacity, and analysts say much of the extra gas the U.S. sends to Europe comes from what should have been exported elsewhere.
The German government called Russia "an unreliable energy supplier". Even though the German government claimed that they have been preparing for the situation for a long time that Russia may stop sending gas one day, experts say it is hard for the EU to replace all of Russia's gas exports any time soon.
The supply and prices of many quartz powder will continue to be influenced by international situations.
What is The Mohs Hardness Scale?
The Mohs Hardness Scale is a standard that indicates the hardness of minerals. It was first proposed by German mineralogist Frederich Mohs in 1822. It is widely used in mineralogy or gemology.
Mohs hardness is a method of scratching the surface of the tested mineral with a pyramidal diamond needle and measuring the depth of the scratch. the depth of the scratch is the Mohs Hardness Scale, represented by the symbol HM. It is also used to indicate the hardness of other materials.
Hardness is expressed by measuring the depth of scratches on a scale of 10 (scratching method):
Mineral |
Chemical formula |
Mohs hardness |
Diamond |
C |
10 |
Corundum |
Al2O3 |
9 |
Topaz |
Al2SiO4(OH−,F−)2 |
8 |
Quartz |
SiO2 |
7 |
Orthoclase feldspar |
KAlSi3O8 |
6 |
Apatite |
Ca5(PO4)3(OH−,Cl−,F−) |
5 |
Fluorite |
CaF2 |
4 |
Calcite |
CaCO3 |
3 |
Gypsum |
CaSO4·2H2O |
2 |
Talc |
Mg3Si4O10(OH)2 |
1 |
The hardness of the tested mineral is determined by comparing it with the standard mineral in the Mohs hardness tester. For example, if a mineral can scratch calcite (3) but not fluorite (4), its Mohs hardness is 3-4.
In the process of determination, it is necessary to make sure that the scratch is actually a scratch, not just a "chalk" mark that will be erased. If the species being tested are fine-grained, fragile or powdery, the test may only loosen the particles without testing the surface of a single mineral; therefore, certain textures or aggregate forms may hinder or hinder true hardness determination.
Mohs hardness value is not absolute hardness value, but relative hardness value, relatively rough. But it is convenient and practical and suitable for field work.
Hardness |
Substance or mineral |
0.2–0.3 |
caesium, rubidium |
0.5–0.6 |
lithium, sodium, potassium, candle wax |
1 |
talc |
1.5 |
gallium, strontium, indium, tin, barium, thallium, lead, graphite, ice |
2 |
hexagonal boron nitride, calcium, selenium, cadmium, sulfur, tellurium, bismuth, gypsum |
2–2.5 |
halite (rock salt), fingernail, mica |
2.5–3 |
gold, silver, aluminium, zinc, cryolite, lanthanum, cerium, jet |
3 |
calcite, copper, arsenic, antimony, thorium, dentin, chalk |
3.5 |
platinum |
4 |
fluorite, iron, nickel |
4–4.5 |
ordinary steel |
5 |
apatite (tooth enamel), zirconium, palladium, obsidian (volcanic glass) |
5.5 |
beryllium, molybdenum, hafnium, glass, cobalt |
6 |
orthoclase, titanium, manganese, germanium, niobium, uranium, rhodium |
6–7 |
fused quartz, iron pyrite, silicon, ruthenium, iridium, tantalum, opal, peridot, tanzanite, rhodium, jade, garnet, pyrite |
7 |
osmium, quartz, rhenium, vanadium |
7.5–8 |
emerald, beryl, zircon, tungsten, spinel |
8 |
topaz, cubic zirconia, hardened steel, spinel |
8.5 |
chrysoberyl, chromium, silicon nitride, tantalum carbide |
9 |
corundum (includes sapphire and ruby), tungsten carbide, titanium nitride, aluminium oxide |
9–9.5 |
silicon carbide (carborundum), zirconium carbide, alumina, beryllium carbide, titanium carbide, aluminum boride, boron carbide |
9.5–near 10 |
boron, boron nitride, rhenium diboride (a-axis), stishovite, titanium diboride, moissanite (crystal form of silicon carbide) |
10 |
diamond, carbonado |
What is a 10 on the Mohs Hardness Scale?
On the Mohs hardness scale, a diamond has a hardness of 10, meaning it is the hardest mineral known to man.
What is a 5 on the Mohs Hardness Scale?
Apatite (enamel), zirconium, palladium, obsidian (volcanic glass).
Is 7 on the Mohs scale hard?
Minerals with Mohs hardness of 7 include osmium, quartz, rhenium, vanadium and so on. They are harder than substances with Mohs hardness less than 7 (such as apatite, calcite, gypsum, etc.) and softer than those with Mohs hardness greater than 7.
Hardness Test
The hardness test developed by Friedrich Mohs is the first known test to evaluate the scratch resistance of materials. This is a very simple but imprecise comparison test. Perhaps its simplicity makes it the most widely used hardness test.
Since the invention of the Mohs hardness tester in 1812, many different hardness testing methods have been invented. These tests include Brinell, Knoop, Rockwell, Shore and Vickers Test. Each test uses a tiny "indenter", which is applied to the material being tested and its force is carefully measured. The hardness value is then calculated by the size of the indentation or the depth and force.
Chemical Supplier
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The war in Russia and Ukraine is roiling global financial markets. Russia and Ukraine are important commodity suppliers in the world, so their conflict is bound to make a full impact on the global commodity supply. In view of this, the price of the quartz powder may continue to rise in the future.
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