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Uses of Minerals. Beauty, Industry, and Health. Gems. Gems are valuable because they are rare and beautiful. Most gems are a special variety of a particular mineral, but they are clearer, brighter, or more colorful than the common sample. Common variety Gem quality variety.
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Uses of Minerals Beauty, Industry, and Health
Gems • Gems are valuable because they are rare and beautiful.
Most gems are a special variety of a particular mineral, but they are clearer, brighter, or more colorful than the common sample. Common variety Gem quality variety
TOPAZ – Rough direct from mine and professionally cut and “heated treated” by jeweler to bring out the blue color. PERIDOT – Rough direct from mine and professionally cut by jeweler.
Gems (like the ruby and sapphire) and the common form (corundum) of the same mineral may have only small chemical differences. • Traces of iron in quartz (left) give amethyst (right) its valuable purple color. • http://www.arkansasquartzcrystals.com/
Corundum Corundum is a very hard mineral (hardness 9); In its rare pure form, corundum is colorless and called white sapphire. Rubies contain chromic oxide, blue sapphires contain titanium along with ferrous oxide, and yellow sapphires contain ferric oxide.
Famous Gems The intense orange phosphorescence of the Hope Diamond is only visible in a dark room after exposure to ultraviolet light. One of the diamonds surrounding the Hope is phosphorescing blue. Photograph by John Nels Hatleberg. http://dsc.discovery.com/news/2008/01/08/hope-diamond.html
530 carat “Star of Africa” diamond http://famousdiamonds.tripod.com/
726 carats (rough) Jonker diamond 125 carats (cut)
The Black Star Sapphire of Queensland Australia • 733 carats of black sapphire, 35 diamonds • Was for sale in 2002 for $100 million dollars • Was found by a 14 year old and originally used as a doorstop http://www.cbsnews.com/8301-205_162-57530642/astronomers-spot-diamond-planet/
Gems are valued based on the 4 C’s: Color, Cut, Clarity, and Carats http://www.palagems.com/quality_4cs.htm Color Clarity Cut • http://mineralsciences.si.edu/collections/newacquisitions.htm • Smithsonian recent acquisitions
Color-saturation Color can range from light to dark. A gem is more valuable the closer its color is to the true color (not pale or so dark it is black). Some gems will even have different color saturation levels within them.
Cut This poorly-cut lemon citrine is windowed.Notice you can read the underlying text through the gem's centre.
The cut can greatly enhance a gem’s appearance. The lime citrine (left) is slightly windowed and very poorly cut. The same gemstone has been recut (right) Notice the ‘fogginess’ of the gem before recut, the small window in the middle and lack of symmetry.
The best cut is selected for each gem based on its starting shape. Rough uncut diamonds
This emerald–cut quartz from Brazil has a blue anatase crystal inclusion as well as needle-like inclusions of rutile. In this specimen, we can see the anatase inclusion seemingly floating in this clear quartz gem. Anatase is a form of titanium dioxide and is usually found as small, isolated, well-developed crystals. Diamond with GarnetSolid inclusions may be the same gem type as the host, or different like the garnet in this diamond.
Thousands of needlelike mineral inclusions create a star-like pattern or cat’s eye pattern (asterism) when the stone is cut properly
Cool Gypsum Crystals-Mexico http://www.thatcrystalsite.com/downloads/NaicaCrystalCave.pps#257,1,Slide 1 http://ngm.nationalgeographic.com/2008/11/crystal-giants/crystals-photography
Useful Minerals • Gemstones are the most popular minerals, but not the most important. • Many everyday objects are made from useful minerals. http://www.oum.ox.ac.uk/thezone/minerals/usage/games/index.htm
Useful Gems Include: • Diamonds are used in cutting tools • Rubies help produce laser light
Ores • A mineral or rock is an ORE if it contains a useful substance that can be mined at a profit. aluminum Bauxite – An aluminum ore
Ores are refined to separate the valuable mineral from the waste material. In Toy Story 3, the metals were separated from the waste materials using a magnet, then the valuable metals were melted down to be recycled and used again.
Mineral Refining 1. Original materials are crushed
2. The crushed rocks are heated or treated with a chemical to separate the waste from the ore
3. Different materials melt at different temperatures or react to chemicals differently • Useful minerals are then separated from the waste rock and are removed.
Mining for ores can be hard on the environment http://maps.google.com/
rutile (titanium dioxide, TiO₂ and ilmenite (FeTiO₃) : Titanium This mineral is light weight and durable Titanium golf clubs can be several hundred dollars Raw titanium Titanium frames are usually over $1000 Titanium body parts
Minerals and Your Health • Many minerals play an important role in maintaining the health of your body. • There are over 14 minerals our body must have to function properly.
Minerals in our body come from the food we eat http://www.healthalternatives2000.com/minerals-nutrition-chart.html
a. Calcium • Helps strengthen our bones and circulate our blood.
b. Copper • Helps our body break down proteins and helps our red blood cells function
c. Iron • Helps produce red blood cells, helps prevent fatigue (tiredness) and protects us from disease.
d. Sulfur • Helps keep our skin, hair, and nails healthy and maintains healthy oxygen levels in our brain.
e. Zinc • Helps with DNA production, converting protein into energy, and helps fight colds
Review • What do we call rare and beautiful minerals? A: Gems