Rocks and Minerals

http://www.conservapedia.com/Amethyst Amethyst is a variety of transparent quartz, used as a gemstone in jewelry. It is a deep clear violet or purple color, and has a hardness rating of 7 on the Moh's Scale.

http://www.conservapedia.com/Biotite Biotite is a common rock-forming mineral of the mica family. Biotite is a black or dark brown silicate rich in iron, magnesium, potassium, aluminum, and, of course, silica.

http://www.conservapedia.com/Crystal A crystal is a substance in which the constituent atoms are arranged in a consistent, repetitive, and therefore orderly pattern. Crystals are extremely common, forming the basis for many rocks and minerals.

http://www.conservapedia.com/Diamond Diamond is an allotrope of carbon, and can be formed when carbon atoms are arranged in a tetrahedral fashion when put under immense amounts of heat and pressure.

A green transparent form of beryl; highly valued as a gemstone.

http://www.conservapedia.com/Feldspar Of all of the minerals in the Earth's crust, the aluminosilicate, feldspar, is the most common. It is a very useful industrial mineral that finds applications in making glass, plumbing fixtures, tile and pottery. These uses in the United States accounted for about 630,000 ton of U.S. produced feldspar valued at about $27.4 million.