The ABCs of
Tanzanite
Tanzanite, a relative newcomer to the market, may lack in rich
gem legend and lore, but it has rapidly won the public's favor since its
discovery some 30 years ago.
No recent gemstone discovery has had more of an impact on the world gemstone
market than tanzanite. Portuguese prospector Manuel d'Souza discovered this gem
in Tanzania in 1967 while searching for sapphire. Tanzanite was named after its
country of origin by Henry Platt, vice president of Tiffany & Co. in New York,
one of the world's most influential jewelers who began an aggressive marketing
campaign to introduce tanzanite to the public in the 1980s.
Tanzanite's mass appeal lies in its great color, a mixture of two gem favorites:
sapphire and amethyst. Popular for its rich violet blue to purple tones,
tanzanite has tonal depth comparable to sapphire. Rarely found in a pure blue,
tanzanite almost always displays purple overtones. It is highly tri-chroic;
that is, it shows varying amounts of blue and violet in incandescent light and
daylight. In small sizes, tanzanite tends toward the lighter tones (lavender is
most common). Tanzanite crystals naturally occur in various colors: yellow,
golden brown green and blue (but rarely).
Tanzanite is a velvety-blue to purple variety of the mineral zoisite, a silicate
of calcium and aluminum. Prior to its discovery, the only variety of zoisite
used for gems was a pink-colored gem known as thulite. A green variety of
zoisite was recently discovered which is called chrome (or green) tanzanite,
owing its color to chromium.
On the Mohs scale of hardness, tanzanite ranks 6-7. This gem is considered
relatively soft and thought should be given when designing jewelry to
protecting the stone from harsh wear. Although its dispersion is low at 0.019,
tanzanite has a moderate luster. Large stones up to 50 carats are available
however, the larger the gem the more saturated the color. Limited quantities of
natural gem-quality tanzanite are found almost exclusively in Arusha, Tanzania.
Warm soapy water and a soft brush is your best bet to clean tanzanite. Do not
use an ultrasonic or steam cleaner. Avoid contact with acids and sudden
temperature changes (as may occur in some jewelry repair and design work). It
is important to buy fine tanzanite from a reputable retailer who will provide,
in writing, all pertinent information regarding the gem including enhancements
and special care notes.
Although it is not a birthstone, tanzanite is a recommended gift for couples
celebrating their 24th wedding anniversary, according to contemporary jewelers'
anniversary gemstone lists. A noted 122.7-carat faceted tanzanite is on display
at the Smithsonian Institution.
Buying Tanzanite
Tanzanite History
View our elegant "Gemstone Jewelry"
