Buying Tanzanite and Determining Tanzanite Gemstone Value
Tanzanite Color
Tanzanite ranges in color from ultramarine to sapphire blue. Under artificial light, it may appear more violet. Tanzanite's pleochroism means that it can appear blue or violet when viewed from different angles. The most desirable color for tanzanite gemstones is a deep saturated blue or violet-blue.
Tanzanite Clarity and Luster
When buying tanzanite gemstones, an eye clean stone should be sought. Tanzanite has an attractive vitreous luster.
Tanzanite Cut and Shape
Tanzanite is mostly faceted in both traditional and fancy shapes and a variety of cutting styles. When cutting tanzanite, lapidarists generally take cost into consideration, which means that tanzanite is often cut into ovals and cushions. The gemstone's main color depends on the orientation of the cut.
Tanzanite Treatment
Tanzanite is usually heat-treated to enhance its blue and violet colors. Most rough crystals show a large proportion of brownish-yellow tints, which vanish when heated to 752-932 degrees F (400-500 degrees C) All reputable gem traders declare such enhancements, however routine they may be.