Discovered only in 1967 in Tanzania, this lovely gem has been a worldwide success, and demand continues to exceed supply. Tanzanite is a variety of zoisite, which is a member of the epidote group. Colors range from blue to purple to green. The most highly coveted color is the deep blue which shows a purple hue shimmering around it.
Tanzanite is trichroic and exhibits pronounced pleochroism. The colors respective to the three vibrational directions are sapphire-blue, sage green, and purple. Orientation is an important consideration for cutters who need to consider both the yield and the resulting color.
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