Tanzanite Gemstone

TANZANITE AS A COSTUME GEMSTONE

Of all the known gemstones tanzanite is probably the newest on the market. Most of stones on the market are blue to lavender in color, generally the result of heat treating. A variety of the mineral zoisite, these stones are found only in the African country of Tanzania, hence the name tanzanite which sounds much more appealing than it proper name, zoisite. The color of the stone will often vary with the angle at which they are viewed. These stones have become highly prized in the gem world with most of the popularity being the result of the single source from which the stones originate.

The stone can be found varieties such as blue, violet, green and party colored. Tanzanite stones are relatively hard though they are prone to damage if not properly cared, mostly due to a nearly perfect cleavage. A stone with perfect cleavage is easily fractured with a single blow. Care must be used to avoid striking tanzanite jewelry and cleaning need only require warm water and soft cloth, so avoid heated cleaning solutions.

History

This stone is considered by some to be the most significant gem marketed in recent history. Discovered in 1967, mining has been confined to a very small area of the country. Ownership squabbles and government intervention have combined to complicate the mining of these stones. The physical process of mining has been very difficult in recent years the result of mine flooding and the availability of stones at shallower depths. This had created a shortage and there are currently a limited number of stones on the market. The limited number of these unique stones has had impact on pricing and the quality of the available stones with high quality stones fetching as much as one thousand dollars per carat to four hundred dollars for smaller stones.

The government of Tanzania, and major gem suppliers have worked very hard to create and maintain a demand for these beautiful stones. No process currently exists to synthesize this stone so the only concern for the buyer is to make that the stone being purchased is tanzanite and not glass, amethyst or other less sought after gemstone.

Birthstone Information

Tanzanite is recognized as the birthstone of the month of December an honor only recently bestowed on this beautiful stone in 2002. This stone shares the honor with other gemstones - turquoise and zircon, not to be confused with the imitation diamond, cubic zirconia.

New Age Beliefs and Powers Through The Ages

Given that tanzanite has a very short history compared with older stones, the stone has not been the subject of mythology or folklore.

Artificial Forms of Enhancement

Heating treating is used as a method to artificially change the color of the stone. There are no other recognized methods of enhancement used at this time.

General Scientific Information

The chemical name Ca2Al3(SiO4)3(OH) also known as calcium aluminum silicate.

Hardness measures between 6 and 7 on the Mohs scale - the Mohs scale measures the hardness of metals, minerals, gemstones and crystals on a scale of 1 to 10. For example the hardness properties of most quartz crystals fall around 7 on the scale, as does steel and titanium. Diamond is the hardest known substance on the Mohs scale coming in at a hard 10. To most consumers hardness generally reflects the stones able to resist scratches and cracks.

The cleavage of tanzanite is perfect.

The index of refraction ranges between 1.692 and 1.700 and generally indicates the purity of the stone.

The specific gravity is 3.35.

The crystalline system is Orthorhombic.