The Gemstone Amethyst
Amethyst is one of the most popular gemstones, and has been considered
valuable since ancient times. Its name derives from the Greek "amethystos",
which means "not drunken", as Amethyst in antiquity was thought to ward
off drunkenness. Amethyst was once highly regarded among
the precious gemstones like Ruby and Emerald, but discoveries of huge
Amethyst deposits since the 1800's have made Amethyst fairly inexpensive
and very obtainable. Amethyst colors range from light to dark purple,
and the transparent deep purple colors are the most highly regarded.
1.54 - 1.55
Transparent to translucent
2.63 - 2.65
Amethyst is the purple variety of the mineral Quartz
, and is its most famous and valuable gem variety. Quartz also contains other gemstones such as Citrine
, Rose Quartz
, and Smoky Quartz
. The color of Amethyst is most often caused by iron impurities
, though it can also be colored by natural radiation
exposure. Amethyst is sometimes heat treated
to deepen the color, or to transform it into Citrine
. Some forms of Amethyst may also change to a light green color upon heat treatment, and such stones are given the name Prasiolite
, or "Green Amethyst
", as it is more commonly known in the gem trade.
Amethyst comes from many different mining sources, some of which produce distinct color styles. For example, Amethyst from Uruguay has a deep purplish-blue color, as does Amethyst from Arizona. Amethyst from Russia, colloquially known as "Siberian Amethyst", is very deeply colored with reddish and bluish tints. It originates from deposits that have since been exhausted and therefore command a high price. Some dealers may sell deeply colored Amethyst from other locations as "Siberian Amethyst" to generate a higher selling value. African Amethyst is generally more deeply colored than South American Amethyst, and the label "African Amethyst" in the gem trade may be improperly used to describe a deeper color stone even if it didn't originate in Africa.
The color distribution of Amethyst is sometimes uneven, and this is often taken into account when cutting a stone. Care should also be taken with Amethyst as it is known to form curve shaped fractures if banged too hard. Some Amethyst from a few locations may slightly fade in color upon prolonged exposure to light.
Amethyst can occur in huge flawless
crystals, and gems of all sizes have been faceted
. Due to the abundance of Amethyst, it is usually clean and free of flaw
s or inclusion
s. Because of this, Amethyst with any visible flaws or inclusions should be avoided.
A natural mixture of purple Amethyst and golden Citrine
has been coined with the trade name "Ametrine". (See the dedicated page for Ametrine
page for more details.)
Amethyst is faceted into many cuts, and is used in all forms of jewelry including rings, necklaces, earrings, bracelets, and pendants. Many large gems weighing several hundred carat
s have been cut from Amethyst. Ornamental objects are occasionally also carved from large pieces. Lower quality Amethyst is an important bead gem and can also be cut into cabochon
s. Tumbled beads of purple Amethyst mixed with white Quartz
are also used as necklaces and bracelets.
Amethyst is the birthstone
- Purple Sapphire
- Purple Sapphire
Treatments & Enhancements
Amethyst is sometimes heat treated
to deepen the purple color and transform lighter colored stones into deeper hues. More often though, Amethyst is heat treated to produce Citrine
and the green Quartz
known as Prasiolite
. Although Amethyst sources are abundant, synthetic Amethyst gems are also produced using the hydrothermal method
Brazil is the largest
producer of Amethyst. It is found there in the states of Minas Gerais, Rio Grande do Sul, Maraba and Bahia. Other important deposits are in Uruguay (in
Artigas), Argentina, Bolivia, Mexico, Namibia, Zambia, South Africa, Madagascar, Canada (Ontario), and the United States (Arizona, North Carolina, Georgia, and Maine). A specific deposit of Amethyst known to produce the greenish Prasiolite
variety upon heat treatment
is the Montezuma Mine in Minas Gerais, Brazil.
The color of Amethyst is rather unique, and few gems are confused with it, especially in deeper shades. Purple Sapphire
and Purple Spinel
may be the same color of Amethyst, but these are both very rare and command much higher prices than Amethyst. Iolite
may also be similar but has a bluer hue. Fluorite
can have the same color, but its very low hardness
limits its use as a gemstone and it is only used as a collectors gem.
Amethyst in the Rough Photos