Natural Deep Blue Tanzanite Faceted Roundel Beads NecklaceSold per 5 inch strand & Sizes from 2mm to 4mm approx.Tanzanite is an extraordinary gemstone. It occurs in only one place worldwide. Its blue, surrounded by a fine hint of purple, is a wonderful colour. Tanzanite is trichroic and exhibits pronounced pleochroism. The colors respective to the three vibrational directions are sapphire-blue, sage green, and purple.