Labradorite is dark gray to gray-black, also green-black with colorful iridescence. There is a Labradorite on the market that is called "Canadian Blue Pearl" or Larvakite. It has been used for many years on the fronts of buildings or in place of marble in bathrooms. As a bead, it is very popular right now.
It is named for the peninsula of Labrador in Canada, where it was first discovered.
The mineral is said to show a "schiller" or "labradorescence" in lustrous metallic tints, often blue and green. Although, specimens with the complete color spectrum do occur and are highly prized.
It is found in Canada (duh!), Australia, Madagascar, Mexico, Russia, Finland and the USA.
Spectrolite is the trade name for a Labradorite from Finland that shows the spectral colors very well.
Lapis Lazuli
Lapis Lazuli is blue, violet or greenish blue. It is basically a sodium calcium aluminum silicate. It is not really a mineral and is considered a rock because it is composed of several different minerals. In addition to Lazurite (25-40%) it may contain Augite, Calcite (the white parts), Diopside, Enstatite, Mica (the shiny parts), Haueynite, Hornblende, Nosean, Sodalite and/or Pyrite (the metallic looking parts). As a result, there are many kinds of Lapis Lazuli. But by far, the most sought after is the deep blue variety with Pyrite and containing no Calcite.
Magnesite is a magnesium carbonate. Crystals are rare, but the massive form is very common. It is frequently an off-white with brown to dark brown veining. It occurs in the coastal ranges of California, also in Nevada and New Mexico. There are some deposits in Canada, as well.
Magnesite is currently being marketed as "White Turquoise", "Buffalo Turquoise" or "White Buffalo Turquoise". It actually has nothing to do with real Turquoise.
There is a chalk turquoise that is very pale and very crumbly. Even though it is very pale, it is still slightly blue and is frequently stabilized and color enhanced.
Malachite
Malachite is banded light green to a very dark black-green. It is a copper carbonate. Most stalactites and stalagmites are composed of carbonates.
Malachite occurs as stalactites, but also as rounded nodules, grape shapes and cone shapes. I have seen one large mass of Malachite that looked for all the world like a big green brain.
The most important deposits used to be in the Ural Mountains of Russia. Today it's found in Zaire, Australia, Chile, Namibia, Zimbabwe and Arizona.
Moonstone
Moonstone is a feldspar. It's basic composition is potassium, aluminum and silicon. All the different colors of moonstone share a white shimmer reminiscent of moonshine. The colors it occurs in are: white, cream, peach, gray, very pale green and rainbow. There is also a very clear variety that shows the rainbow shimmer.
