What is Tanzanite Stone?

About Tanzanite

• Tanzanite is named after the East African state of Tanzania, the only place where this gemstone appears. It is said to have been first discovered in the shadows of Mount Kilimanjaro in 1967. Tanzanite is made from the mineral zoisite, which contains calcium, aluminum, oxygen, hydrogen and silicon, according to the website WebMineral.

  This zoisite is processed with heat to produce the rich blue-violet color commonly associated with tanzanite stones. In nature, the stones can vary in color in browns, reds, blues and yellow-ish-greens. Tanzanite is not a particularly hard stone, so it must be worn with care and protected from impact and hard use.

Tanzanite Processing

• Though some of the tanzanite in the recognizable bluish-purple shade occurs naturally, most tanzanite stones have been treated to achieve that distinctive color. Generally, the stones are cut and polished prior to being heated at temperature of 700 degrees Fahrenheit, according to TheGemSociety website. This fixes the color permanently. All commercially-sold tanzanite stones are assumed to be heat-treated, though it is sometimes nature that provides the heating. Generally larger stones produce more violet color, while small stones produce bluer tones.

Stone Quality

• The most valuable tanzanite stones are those with rich, deep color, whether purplish-blue or bluish-purple. Clarity is an important factor, that is, stones that are without marks or muddiness. Paler colors of tanzanite blue are often found but these do not garner the high prices of color-rich stones. Ensure that the tanzanite stone you are considering for purchase is a real natural tanzanite. Lab-created tanzanites, called tanzaniques, are available and mimic the tanzanite color but are not as valuable.

Buyting Stones

• Because tanzanite stones are found in only one location in the world, buyers may encounter many exaggerated claims of their rarity and value. Always buy from reputable dealers with an established name in the gemstone business. Larger stones often have the best color, so choose these over smaller stones when possible. Be particularly careful when purchasing tanzanite stones while stopping in countries on cruises. It may be difficult to evaluate the reputation of the seller. Beware of sellers using the name of better-known gemstone companies that have no true connection with that company.