Chalcedony

A crypto-crystalline sub-species of quartz. It is generally of a milky brown colour, but there are also rarer blue (blue chalcedony), green (chrysoprase) and orange-red (cornelian) varieties. Very occasionally it may be transparent.

Agate is frequently stained to resemble types of chalcedony; so particular care should be taken when buying chalcedony that you are not, in fact, about to be sold an imitation.

The mineral is found in Madagascar, Brazil, India, China and the USA.

Azurite

Azurite is a blue carbonate mineral, chemically composed of copper carbonate hydroxide. It is found associated with green mineral malachite as an aftermath of weathering and oxidation of copper sulfide minerals. The name of the stone is derived from the Arabic word for blue.

Azurite is also commonly called 'Blue Bice' and 'Blue Verditer.' Formerly it was known as Azurro Della Magna, taken from Italian words. The stone turns slightly green when mixed with oil and green-grey, when mixed with egg yolk.

Azurite in beautiful crystals form are found in the United States in the Arizona and New Mexico. In France it is found at Chessy and is sometimes called chessylite. It is used for ornamental purposes, as a dye for paints and fabrics for eons.

The stone is a powerful healing stone which invokes spiritual guidance and opens psychic eye. It is also good for dreams and improving psychic ability. The magnificent color is considered to be unique in the mineral world.

Apatite

Apatite is a naturally occurring gemstone. It is basically known for its asparagus green color but it is found in wide range of colors, from colorless to pink, yellow, blue to violet. The best apatite is neon greenish blue with a clean clarity. The cost of the stone increases with the intensity of the color.

Apatite's property is fairly soft and is rarely used for rings, but is very popular as earrings and pendants because of its unusual intense green color. The hardness of the stone is 5 to 6.5 on Moh's scale. It has a vitreous luster and is sensitive to acids.

The name, 'apatite' has been taken from a Greek word 'apate,' which mean to deceive. It is so named because one can be easily get confused with variety of other stones like tourmaline, peridot and beryl.

Apatite is found in Burma, Brazil, India, Madagascar, Kenya, Mexico, Norway, Sri Lanka, South Africa, and the United States.

Apatite is found in all igneous, sedimentary and metamorphic rocks. It can also be cut as gems but the softness of apatite prevents its acceptance as a gemstone.

Ametrine

Partially it occurs to be purple and partially orange-yellow. It is typically given a rectangular shape with a 50-50 pairing of amethyst and citrine. So, with ametrine one can have the color of two gems for the price of only one.

Ametrine is very popular among the artistic cutters and carvers. They play with its colors, creating landscapes in the stone. Sometimes, the artists give a checkerboard pattern to the top, which increases the light reflection.

Ametrine is durable and is suited for a variety of jewelry uses. The sizes and shapes are also available in abundance and the color contrast is mainly pronounced in sizes over seven carats. Taking into account of its availability from a single mine, it is not so expensive.

Ametrine helps in achieving a balance between the spiritual and the material world. It is also used to enhance the cooperation with others. It gives higher mental opening for meditation and inspiration.

It is of a pale lilac, mauve or bluish violet colour. Very popular in the past, its current value is stable as new mines have recently been discovered. Moreover, its worth has been further undermined over recent years by the flood of tasteless objects made in Brazil.

The best investment is an amethyst of average size weighing between 4 and 8 carats, as dark as possible, but not so much so that the light is prevented from reflecting, and with a deep lustre.

Amber

It is found in many colours and may be both translucent or opaque. The rarest specimens are those enclosing insects of extinct species and leaves trapped in the sticky exudations of the tree.

Amber occurs practically everywhere in the world, but not in large quantities. It is most abundant, however, in the Baltic regions of Northern Europe.

Unlike most other stones, its impurities actually increase its value, but be suspicious of so-called "pressed" or "compressed" amber.

It is generally cut en cabochon or left in its original shape and simply polished. Ever since ancient times, it has been used for making beads for necklaces and bracelets.