A gemstone is any rock or mineral that could be used for ornamentation or jewelry.  Most often, minerals are cut and polished to bring out the natural beauty of the piece.  Even diamonds must be cut into their familiar faceted shapes to really sparkle (uncut versus cut shown below). 

	Gemstones are rare and beautiful.  Colorado has over thirty different varieties of gems and ornamental stones, including diamonds, rhodochrosite and aquamarine.