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Roger Weller, geology instructor

wellerr@cochise.edu

Mohs Scale
by Emilee Stevens
Physical Geology
Fall 2009
  
                                        Mohs Scale of Hardness

The Mohs Scale of Hardness the scale that measures the hardness of particular minerals ranging from the hardest mineral to the softest mineral. Not many people have heard of it before but how often do we think about the degree of hardness in the minerals we use everyday? These next few paragraphs will show you how often we actually use/see these minerals in our everyday life.

1. TALC

http://www.golcha.com/uses.htm            http://geology.com/minerals/talc.shtml
 

“Talc is the world’s softest mineral and the lowest mineral on the Mohs scale” ("All About Gemstones.").  It has a glistening shine and is impossible to dissolve in water. Many people think of talc in the most common form, talcum powder. Talc is also commonly found in paint, paper, pharmaceuticals, cosmetics, detergents, animal feed, asphalt, bleaching agents, and dry fire extinguishers. It is all around us and we don’t even realize how much we depend on this mineral to do everyday stuff.
 

2. GYPSUM

Both pictures from http://geology.com/minerals/gypsum.shtml
 

“Gypsum is a soft mineral composed of calcium sulfate dehydrate. Gypsum occurs in nature as flattened or twinned crystals and transparent cleavable massed called selenite” ("All About Gemstones."). Gypsum is limited in its uses because of its durability. Some uses of gypsum are plaster of Paris, the manufacture of wallboard, fertilizer, and “it has even been used in ancient times as a replacement for wood when deforestation made building material hard to obtain” ("eHOW:How To Do Just About Everything.").
 

3. CALCITE

All photos from http://geology.com/minerals/calcite.shtml
 

“Calcite is an anhydrous carbonate, and one of the most widely distributed minerals on the Earth’s surface” ("All About Gemstones."). Calcite is commonly found in limestone and marble which makes up a large portion of the Earth’s crust.  It “…serves as one of the largest carbon repositories on our planet” ("geology.com." Apatite). Other common uses for calcite are as a dietary supplement in animal feed, coloring for paint (when in powder form), cleaning agents for around the house that won’t damage surfaces, antacids like Tums, on the walls of coal mines, caverns,  soil treatment, and for cement and concrete.
 

4. FLUORITE

http://www.mineralszone.com/minerals/fluorite.html    http://geology.com/minerals/fluorite.shtml


Fluorite is a very common mineral that is used often in our everyday lives. Fluorite is a fluorescent  mineral that has a cubic crystal structure. Fluorite is used in manufacturing steel, hydrofluoric acid, telescope and camera lens, ornaments, enamels for cooking utensils and much more. Fluorite occurs all over the world. There are at least ten states in the United States where fluorite occurs; Arizona is one of them.

 

5. APATITE

All pictures from http://geology.com/minerals/apatite.shtml

 

 “Apatite (hydroxylapatite, fluorapatite, chlorapatite)…is one of the few minerals that are produced by biological organisms” (“All About Gemstones.").  Our bones and teeth are mostly comprised of apatite. The primary use of apatite is in fertilizer because it is rich in phosphorus. People who garden or farm rely on the apatite in their fertilizer to help make their plants grow.  Apatite is sometimes seen as a gemstone.
6. ORTHOCLASE

   Picture from http://skywalker.cochise.edu/wellerr/mineral/feldspar/feldspar3.htm
 

Orthoclase, better known as feldspar, is a main component in granite. Most commonly, orthoclase is used in porcelain, glass and china. The bodies of porcelain dolls are often made of orthoclase materials. It is ground to a fine powder and placed in the mixture to make the bodies. Most of the orthoclase-feldspar used in the United States is by the ceramic and glass industries. If too much of the mineral is added, the dolls become very brittle and have a glassy type of texture.
 

7. QUARTZ

All pictures from http://geology.com/minerals/quartz.shtml
 

“Quartz is one of the most common minerals found in the Earth’s crust” (“All About Gemstones."). Quartz valuable because of its ability to withstand heat. It is used in bricks because of its high heat resistance. Petroleum industries use quartz to help with the flow of gas and oils. “Quartz sand is used in the production of container glass, flat plate glass, specialty glass and fiberglass” ("geology.com." Quartz Mineral Uses & Properties.). Quartz is used as a gemstone that can come in many different colors. The most common color of quartz gemstone is the rose quartz. In the Indian times, quartz was used to make sharp objects like arrowheads and knives because of its hardness.
 

8. TOPAZ

All pictures from http://geology.com/minerals/topaz.shtml
 

Topaz is commonly used as a gemstone. Topaz comes in a variety of colors including pink, brown, red, blue, green or yellow. Red and pink do happen but are very rare colors to find in topaz. Sometimes brown topaz will be treated and can be made into a pink color. Red and pink are the most expensive color topaz on the market today because of their rarity.
 

9. CORUNDUM

All pictures from http://geology.com/minerals/corundum.shtml
 

Corundum is better as the gemstones ruby and sapphire; because of its hardness,  Corundum is also used in grinding wheels, cutting tools and most commonly in sandpaper. The deep red color of corundum is called a ruby. Many other colors are formed but the most common color ruby is red. As for sapphire, the most common color created is blue. “…The word “sapphire” always refers to a deep blue corundum” ("geology.com." Corundum Mineral Uses & Properties.). 
 

10. Diamond

All photos from http://geology.com/minerals/diamond.shtml


The most widely known mineral is the diamond. It is the hardest mineral on the Mohs scale of hardness. At one point or another, almost everyone will have owned a diamond in their lifetime. Diamonds are commonly seen in jewelry but it is also used for more than just making people look pretty. “Small particles of diamond are embedded in saw blade, a drill bit or a grinding wheel for the purpose of cutting, drilling or grinding. They might also be ground into a powder and made into a diamond paste that is used for polishing or for very fine grinding” ("geology.com." Diamond Mineral Uses & Properties).

While all of these minerals have purposes in one way or another, not every mineral is used in our daily lives. If we look close enough at the products we are using, there is a good chance that at least one of these ten minerals helped make it or is  contained in that particular product. We may not see it but these minerals are around us and if we look close enough we will find them.


 

 

                              Works Cited

"All About Gemstones." Mineral Hardness: Mohs Hardness Scale. N.p., 2009. Web.
     22 Nov. 2009.
            http://www.allaboutgemstones.com/mohs_hardness_scale.html
"Department of Ecology:State of Washington." Apatite. N.p., n.d. Web. 22 Nov.
     2009.  http://www.ecy.wa.gov/programs/nwp/apatite.htm
"eHOW:How To Do Just About Everything." Uses for Gypsum. N.p., n.d. Web. 22 Nov.
     2009.  http://www.ehow.com/facts_5455420_uses-gypsum.html
    ?ref=fuel&utm_source=yahoo&utm_medium=ssp&utm_campa
     ign=yssp_art>.

Feldspar Photos. N.p., n.d. Web. 23 Nov. 2009.
          http://skywalker.cochise.edu/wellerr/mineral/feldspar/feldspar3.htm
"geology.com." Apatite - Mineral Properties and Uses. N.p., n.d. Web. 22 Nov.
     2009.  http://geology.com/minerals/apatite.shtml
"geology.com." Calcite Mineral Uses & Properties. N.p., n.d. Web. 22 Nov. 2009.
       http://geology.com/minerals/calcite.shtml
"geology.com." Corundum Mineral Uses & Properties. N.p., n.d. Web. 22 Nov. 2009.
     http://geology.com/minerals/corundum.shtml
"geology.com." Diamond Mineral Uses & Properties The world's most popular
     gemstone. -- The hardest natural substance known. N.p., n.d. Web. 22 Nov.
     2009.  http://geology.com/minerals/diamond.shtml
"geology.com." Gypsum - Mineral Properties and Uses. N.p., n.d. Web. 22 Nov.
     2009.  http://geology.com/minerals/gypsum.shtml
"geology.com." Quartz Mineral Uses & Properties. N.p., n.d. Web. 22 Nov. 2009.
     http://geology.com/minerals/quartz.shtml
"geology.com." Topaz Mineral Uses & Properties. N.p., n.d. Web. 22 Nov. 2009.
     http://geology.com/minerals/topaz.shtml
 "geology.com." Topaz Mineral Uses & Properties. N.p., n.d. Web. 22 Nov. 2009.
     http://geology.com/minerals/topaz.shtml
"Golcha Associated Group." Uses of Talc. N.p., n.d. Web. 22 Nov. 2009.
     http://www.golcha.com/uses.htm
"Minerals Zone: World Mineral Exchange." Feldspar. N.p., n.d. Web. 22 Nov. 2009.
     http://www.mineralszone.com/minerals/feldspar.html
"Minerals Zone: World Mineral Exchange." Fluorite. N.p., n.d. Web. 22 Nov. 2009.
     
http://www.mineralszone.com/minerals/fluorite.html