Milky quartz derives its distinctive milky white or cream color from inclusions of gas and

Citrine is the yellow or golden yellow variety of quartz. The yellow coloration, due to

Aventurine quartz contains inclusions of small crystals that reflect light, and which give a range

Crystalline quartz in shades of purple, lilac or mauve is called amethyst, a stone traditionally

Quartz is the second-most-abundant mineral in the Earth’s continental crust, after feldspar. It is made

The name pyrite comes from the Greek word pyr, meaning fire, since sparks are caused

Often an oily green, prehnite may also range from pale yellowish to brown. Columnar or

Gem quality specimens of the mineral olivine are called peridot by gemmologists. Peridot has an

Zircon is most famous for its colorless stones, which closely resemble diamonds and have been

Tanzanite is the blue/purple variety of the mineral zoisite (a calcium aluminium hydroxy silicate) which

Opal is  mineraloid gel, usually containing 5 – 10 percent water. It is therefore non-crystalline,

Zoisite occurs in a number of varieties, the most sought-after being tanzanite, a variety colored

Natural glass is formed naturally without the intervention of man. Its primary composition is silica

Meerschaum, also called sepiolite, is an extremely fine-grained, soft, light rock. Found as compact, opaque

Malachite is usually found in opaque green masses; the color is due to the copper