The Tanzanite Gem is, of the three varieties that Zoisite has, the most important. It is an aluminum and calcium silicate belonging to the group of the epidote.
When it is of good quality Garnet Gem presents a color of ultramarine blue to sapphire blue. Under artificial light the color is of an amethyst violet. It is a stone of a very intense pleochroism . The tricróicos colors that can be appreciated with the naked eye are: blue, purple red and yellow-greenish brown.
The color is violet brown due to vanadium and by heating it turns blue which is how it is marketed. The brightness is vitreous. Despite their color, they are very transparent.
Its hardness is from 6.5 to 7 on the Mohs scale.
Physicochemical properties of Lab Created Diamonds
Rainbow Gemstone is a silicate and can occur in the form of granular, massive and fibrous masses. When tanzanite occurs in the form of crystals, they have a prismatic or tabular appearance, often showing striations and evident cleavage planes.
The brightness of this mineral is vitreous and its hardness is 6 on the scale of mohs, which is optimal to work as a precious stone.
Lab Grown Diamonds crystallizes in the rhombic system, exfoliates easily and has no fluorescence. one of its characteristics is that it has pleocroism with three colors of certain intensity.
This mineral is attacked by hydrochloric and hydrofluoric acids.
The Tanzanite is a mineral that occurs with few inclusions, but in certain exemplary needle - like inclusions of tremolite may occur.
Depending on the amount of acicular tremolite inclusions, these can make tanzanite present the particular cat eye effect.
Formation of Loose Sapphire Stones
It is located on the slopes near Mount Kilimanjaro. where metamorphic rocks, marbles and schists appear that belong to the organic belt of Mozambique.
The tanzanite is found in pegmatite veins where it usually appears together with quartz, garnets and feldspar.
The only deposit of tanzanite is in Tanzania, but due to its overexploitation it is foreseen that only a few years the deposits are exhausted, are located in the town of Merilani in the district of Lelatama.
Gemology of tanzanite
Currently the tanzanite is a gem more sought after, because of its beauty; the best specimens are destined for high level jewelry reaching high prices even more than some diamond specimens.
The tanzanite looks better in oval size, although rectangular and round sizes are also used. Other sizes that are used are fantasy carvings, in the form of flower and heart.
The size in cabochon is usually used to highlight the cat eye effect that some particular pieces present.
Imitations of the tanzanite
- The tanzanite can be imitated with the cordierite, even though this gem is not completely violet.
- It can also be confused with some specimens of sapphire, but the latter is much harder.
- It is well imitated by colored glasses or doublets formed by two pieces of synthetic spinal.
The tanzanite is the birthstone of December
The American Gem Trade Association introduced in the year 2002, for the first time the Tanzanite in the month of December along with turquoise and lapis-lazuli. In addition, this gem is linked to the 24th wedding anniversary in couples.