Ametrine

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Jewelry 101--Colored Stones

Ametrine

Ametrine, the word and the stone, is a combination of amethyst (purple) and citrine (yellow), both of which are varieties of the mineral quartz. Fine quality ametrine exhibits a sharp color change located in the center of the gem. As with other gems in the quartz family ametrine is a hard durable gemstone suitable for daily wear.

Amentrine is also known as trystine or by its trade name as Bolivianite.
A naturally occurring variety of quartz, amentrine is a mixture of amethyst and ctrine with zones of purple and yellow or orange.
The only significant source of ametrine is the Anahí Mine in Bolivia. Although known to the natives for several hundred years, it is only since the 1980’s that it has been worked on a commercial level.
Most often cut to produce a stone half purple and half golden, sometimes both colors are present as a mixture or in different ratios. Sometimes the stone is cut in a checkerboard pattern with some facets golden and others purple.
Ametrine is a macrocrystalline variety of quartz that occurs rarely in nature.
For ametrine to occur naturally, iron impurities--combined with differing oxidation states--are subjected to varied temperatures. For ametrine to be formed in nature, temperatures need to be slightly higher on some of the surfaces, slightly cooler on others and the delicate balance of the two temperatures would need to be maintained during the crystallization of the quartz.
Simulated ametrine is created when amethyst is subjected to the same type of conditions in the lab, turning purple areas various shades of yellow. Most ametrine in the market today is heat-treated amethyst.

Specs

Chemical Formula	SiO₂	Mineral Class	Quartz
Color	Multi-colored, yellow and purple
Crystal System	Hexagonal	Hardness	7
Transparency	Transparent	Luster	Vitreous
Refractory Index	1.544 - 1.553	Double Refraction	0.009

Legends

Legend has it that ametrine was first introduced to Europe by a conquistador’s gifts to the Spanish Queen, after he received a mine in Bolivia as a dowry when he married a princess from the native Ayoreos tribe.

Ametrine is said to be the complete balance of the properties of amethyst and citrine. As a stone of both balance and connection, ametrine is believed to relieve tension, bring serenity and stimulate creativity, as well as balance mental stability and self-confidence. Ametrine is considered a double boost to remove toxins from the body, as both amethyst and citrine are detoxifiers.

The world’s only commercial source of ametrine is the Anahi mine in southeastern Bolivia. Legend has it that a Spanish conquistador discovered the mine’s location in the 1600s and introduced the gem to Europeans when he presented several specimens to his queen. The mine had been given to him as a dowry when he married a native princess named Anahi. After that, the mine was lost for more than three centuries. Rediscovered in the 1960s, the mine’s ametrine began appearing on the market again during the 1970s. Today the mine, named Anahi for the legendary princess, also produces natural amethyst and citrine.