Calcite

aka Iceland Spar, Calcspar, Lime Spar, Nailhead Spar, Pineapple Jasper, Mexican Jade, Flowstone, Cave Onyx, Mexican Onyx

Calcite is the one of the most common minerals on earth, constituting about 4% by weight of the Earth’s crust. The name calcite comes from a Greek word chalx, meaning "lime." This name is taken from the stone's chemical component, calcium carbonate, which sometimes is mistakenly known as lime. It usually brings to mind a clear or whitish stone, but calcite also occurs in a seemingly unlimited variety of shapes and colors. Calcite is often fluorescent, and a small amount of manganese is enough to make it glow red under UV light. Another interesting feature of the stone is its strong double refraction — a phenomenon that occurs when a light ray enters the crystal and splits up into two separate rays, making anything observed through the crystal appear as double. Transparent clear dolomite is indistinguishable from calcite unless complicated optical tests are performed. It can also be distinguished by the fact that dolomite only effervesces with warm hydrochloric acid, and calcite with cold, but accurate results of this test are hard to get. Ultrasonic cleaning is risky for this relatively soft gemstone, and steaming is a big no-no; cool soapy water is the safest cleanser for calcite, but avoid water with a low-pH acidic nature.

Almost all of the "alabaster" artifacts of ancient Egypt are actually made of calcite. The gemstone was even used as an inlay on the throne in the tomb of King Tutankhamen, which dates to around 1340 B.C. Mystics today consider calcite to be an energy amplifier. It is said to give a polarizing prismatic energy, which produces a spectrum of energy to clear and to activate all of the chakras. It also is supposed to be a balancing agent for the assimilation of calcium in the body, thus helping with either osteoporosis or problems with calcification of organs. Mexico and the U.S.A. are the major sources of calcite, but it is found in smaller quantities around the world.