Can radioactive dating used metamorphic rocks
Trace amounts of vanadium, mixed with extreme heat, cause the blue color – which ranges from pale blue to intense ultramarine with violet undertones.
Due to pleochroism, tanzanite can display different colors when viewed from different angles.
Treated tanzanite has become the norm, so although it’s undetectable, it’s usually assumed.
Generally, tanzanite follows the same value parameters as diamonds.
Most faceted tanzanite weighs less than five carats.
Stones heavier than 50 carats are rare, although The Smithsonian Institution’s collection includes a faceted 122.7-carat tanzanite.
Tanzanite One Mining Ltd., the world’s largest tanzanite producer, holds the rights to Block C, which is larger than the other blocks combined.
An independent study from 2012 suggests, at a production rate of 2.7 million carats per year, that Block C’s tanzanite deposits may deplete in as soon as 30 years.
Instead of publicizing “blue zoisite” – which sounded a little too much like “suicide” – Tiffany named the gem tanzanite to highlight its exclusive geographic origin, and introduced it with a promotional campaign in 1968.
Between its deep blue color and its limited supply, tanzanite is treasured by many – whether one is born in December or not!
Unlike many well-known gems that have been in use for centuries, tanzanite’s history is relatively modern.
Buying from a reputable AGS jeweler will ensure that you get what you pay for.
Color, of course, is tanzanite’s most prized trait, especially when it’s deeply saturated blue with violet hues. Tanzanite is pleochroic, which means it displays different colors from different angles.