Mohs Scale Of Mineral Hardness - Simple Wikipedia

Jump to content

Contents

move to sidebar hide

• Beginning
• 1 Relative hardness of some items
• 2 References
• 3 Other websites

• Page
• Talk

English

• Read
• Change
• Change source
• View history

Tools Tools move to sidebar hide Actions

• Read
• Change
• Change source
• View history

General

• What links here
• Related changes
• Upload file
• Permanent link
• Page information
• Cite this page
• Get shortened URL
• Download QR code
• Switch to legacy parser

Print/export

• Make a book
• Download as PDF
• Page for printing

In other projects

• Wikimedia Commons
• Wikidata item

Appearance move to sidebar hide From Simple English Wikipedia, the free encyclopedia

Mohs' scale of mineral hardness is named after Friedrich Mohs, a mineralogist. Mohs scale is ordered by hardness, determined by which minerals can scratch other minerals.[1]

Rocks are made up of one or more minerals. According to the scale, Talc is the softest: it can be scratched by all other materials. Gypsum is harder: it can scratch talc but not calcite, which is even harder. The hardness of a mineral is mainly controlled by the strength of the bonding between the atoms and partly by the size of the atoms. It is a measure of the resistance of the mineral to scratching, the Mohs scale is for natural minerals. For manufactured products other measures of hardness are better.[2]

Diamond is always at the top of the scale, being the hardest mineral. There are ten minerals in Mohs scale, talc, gypsum, calcite, fluorite, apatite, feldspar, quartz, topaz, corundum, and for last and hardest, diamond. Because the Mohs scale was made long ago, it is not exactly correct – for example, several minerals are now known to be harder than corundum (at 9 on the scale).[3] The Mohs scale may not be perfect, but field geologists still find it very useful.

Mohs hardness	Mineral	Chemical formula	Absolute hardness[4]	Image
1	Talc	Mg3Si4O10(OH)2	1
2	Gypsum	CaSO4·2H2O	2
3	Calcite	CaCO3	9
4	Fluorite	CaF2	21
5	Apatite	Ca5(PO4)3(OH–,Cl–,F–)	48
6	Feldspar	KAlSi3O8	72
7	Quartz	SiO2	100
8	Topaz	Al2SiO4(OH–,F–)2	200
9	Corundum	Al2O3	400
10	Diamond	C	1500

Relative hardness of some items

[change | change source]

2.5 Fingernail 2.5–3 Gold, Silver 3 Copper penny 4–4.5 Platinum 4–5 Iron 5.5 Knife blade 6.5 Iron pyrite 5.5 Glass 6.5 Hardened steel file [5]

References

[change | change source]

1. ↑ "Mohs Hardness Scale: Testing the Resistance to Being Scratched". geology.com. Retrieved 2020-03-09.
2. ↑ NDT Resource Center: hardness.
3. ↑
4. ↑ Applied Mineralogy: applications in industry and environment. Swapna Mukherjee 2011
5. ↑ Mohs scale of Hardness, https://www.amfed.org/mohs-scale

Other websites

[change | change source]

• http://www.mineraltown.com/infocoleccionar/mohs_scale_of_hardness.htm
• How to use the Mohs scale of mineral hardness Archived 2006-12-30 at the Wayback Machine

Retrieved from "https://simple.wikipedia.org/w/index.php?title=Mohs_scale_of_mineral_hardness&oldid=9793074" Categories:

• Minerals
• Tests
• Materials science

Hidden category:

• Webarchive template wayback links

Search Search Toggle the table of contents Mohs scale of mineral hardness 73 languages Add topic