tanzanite
you can view the standard shapes below. for detailed
information and prices, please click here.
tanzanite is the mineral zoisite. discovered some 20 years ago in the foothills of mount kilimanjaro in east africa (in tanzania), this exciting violet gem has become very popular. tanzanite is a tri-chroic gem, meaning that it has 3 colors. when mined it is violet, blue, and brown, depending on the viewing axis (direction of viewing). the rough is heated which changes the brown to blue, so you will see gems with either a predominantly blue or violet color depending on the direction of cutting.
history
unlike many other gemstones, tanzanite does not have a mystical ancient history. it was first found in the late 1960's, at what remains the sole source: a hilly area called merelani in tanzania. this gemstone was introduced in the world market by tiffany's in new york, who changed its name from "blue zoisite" to tanzanite - in honour of its country of origin. there are many colors that can be seen in a tanzanite. this is because it is a trichroic gem. very few stones are trichroic and this is what makes tanzanites very easy to identify. trichroic refers to three layers of color. the more common layers are blues and purples but you may also see flashes of red, green, yellow, orange, or brown. the color that gemologists predominantly speak of is the "deep royal blue". keep in mind that most tanzanites have a distinct shift in color with different types of lighting.
tips for purchasing tanzanite
- always clean the stone first. dirt and fingerprints hide color and brilliance.
- examine the stone face up against a variety of backgrounds. look straight down at it against a white background and check if the center of the stone is pale and washed out. (this is undesirable). then examine against a black background. do you still see the same colors or do they disappear?
- examine the stone with different lighting; natural versus synthetic lighting. look at it under dark lighting (shaded areas).
- check the stone from the side to look for what is called color zoning. if the color is uneven this decreases the value of the stone. have the store explain about hue and color purity when you compare price. this is where most of the stones purchased in the islands come up short.
- always look at a stone with a 10x power loupe. this will help you see the color depth as well as any defects that may be in the stone.
pricing
hues that range from blue to violet blue command the highest prices. the majority of people prefer colors that look closer to a blue sapphire. tanzanites that have a strong purple color and look like amethyst stones are much cheaper to buy. i have really stressed color because this is the most important pricing factor for
tanzanites.
always compare price per carat when pricing colored stones. otherwise it will be difficult to make an accurate comparison. very high quality stones demand high prices because they are very rare. it is always best to let the jeweler know what your pocket book can handle or you may be very surprised. remember that there is no standard system for grading colored stones. this is why it is wise to look at many stones and compare prices before purchasing what you think is a good deal. it is best to establish a relationship with your jeweler because they will help you find values that you would rarely find on your own.