.7" Blue-Violet Tanzanite Crystal Cluster - Merelani Hills, Tanzania

This is a gorgeous, .7" wide tanzanite crystal cluster that was collected from the Merelani Hills in the Manyara Region of Tanzania. They exhibit a blue color from one angle and a violet color from another. This pleochroic effect is evident when backlighting the crystals.

It has been mounted to an acrylic display base with mineral tack.

Tanzanite is a blue-violet variety of zoisite that gains its color from the substitution of vanadium within the zoisite mineral structure. It is found only in the Arusha and Manyara regions of Tanzania, Africa, which it is named after. It is well known and relatively popular in the gemstone community for its lovely color and pleochroic effect when viewing from different angles. The pleochroism of a tanzanite crystal is taken into account prior to faceting into a gemstone to ensure it's cut at an angle that delivers the strongest blue-violet color. Tanzanite is relatively soft for a gemstone, so its uses in jewelry are somewhat limited.

Zoisite belongs to the epidote group of minerals and its chemical formula is Ca2Al3(SiO4)(Si2O7)O(OH) (calcium aluminium hydroxy sorosilicate). It can be found in a variety of colors including green, pink, brown, yellow, grey, white, blue, purple or colorless. The color it bears is dependent on the ion substitutions within the crystal lattice, for example; thulite is a pink variety of zoisite that gains its pink color from manganese substituting for calcium within the crystal lattice.

Zoisite was originally known as saualpite.
Zoisite var. Tanzanite
Merelani Hills, Lelatema Mountains, Manyara Region, Tanzania
.7" wide