About Gemstones

Diamonds.
Diamonds were first mined in India.  Pliny may have mentioned them, although there is some debate as to the exact nature of the stone he referred to as Adamas;  In 2005, Australia, Botswana, Russia and Canada ranked among the primary sources of gemstone diamond production.
The British crown jewels contain the Cullinan Diamond, part of the largest gem-quality rough diamond ever found (1905), at 3,106.75 carats (621.35 g).

Many different precious and semiprecious stones are used for jewelry. Among them are:

Amber
Amber, an ancient organic gemstone, is composed of tree resin that has hardened over time. The stone must be at least 1 million years old to be classified as amber, and some amber can be up to 120 million years old.

Amethyst
Amethyst has historically been the most prized gemstone in the quartz family. It is treasured for its purple hue, which can range in tone from light to dark.

Emerald
Emeralds are one of the three main precious gemstones (along with rubies and sapphires) and are known for their fine green to bluish green color. They have been treasured throughout history, and some historians report that the Egyptians mined emerald as early as 3500 BC.

Jade
Jade is most commonly associated with the color green, but can come in a number of other colors as well. Jade is closely linked to Asian culture, history, and tradition, and is sometimes referred to as the stone of heaven.

Jasper
Jasper is a gemstone of the chalcedony family that comes in a variety of colors. Often, jasper will feature unique and interesting patterns within the colored stone. Picture jasper is a type of jasper known for the colors (often beiges and browns) and swirls in the stone’s pattern.

Quartz
Quartz refers to a family of crystalline gemstones of various colors and sizes. Among the well-known types of quartz are rose quartz (which has a delicate pink color), and smoky quartz (which comes in a variety of shades of translucent brown). A number of other gemstones, like Amethyst and Citrine, are also part of the quartz family. Rutilated quartz is a popular type of quartz containing needle-like inclusions.

Ruby
Rubies are known for their intense red color, and are among the most highly valued precious gemstones. Rubies have been treasured for millennia. In Sanskrit, the word for ruby is ratnaraj, meaning king of precious stones.

Sapphire
The most popular form of sapphire is blue sapphire, which is known for its medium to deep blue color and strong saturation. Fancy colored sapphires in various colors are also available. In the United States, blue sapphire tends to be the most popular and most affordable of the three major precious gemstones (emerald, ruby and sapphire).

Turquoise
Turquoise is found in only a few places on earth, and the world’s largest turquoise producing region is the southwest United States. Turquoise is prized for its attractive color, most often an intense medium blue or a greenish blue, and its ancient heritage. Turquoise is used in a great variety of jewelry styles. It is perhaps most closely associated with southwest and Native American jewelry, but it is also used in many sleek, modern styles. Some turquoise contains a matrix of dark brown markings, which provides an interesting contrast to the gemstone’s bright blue color.

Some gemstones (like pearls, coral, and amber) are classified as organic, meaning that they are produced by living organisms. Others are inorganic, meaning that they are generally composed of and arise from minerals.

Some gems, for example, amethyst, have become less valued as methods of extracting and importing them have progressed. Some man-made gems can serve in place of natural gems, an example is the cubic zirconia, used in place of the diamond.