History & Introduction
Tourmaline is the gemmological name given to the complex gem-quality of silicate
minerals. It is available in the vivid colors of rainbow. Due to this wide range
of color availability, tourmaline is considered to be one of the versatile gemstones
found today in the market. Tourmaline is derived from the Sinhalese word, "turamali",
which means "stone with various colors."
Around 1500s tourmaline was first thought to be used as a gemstone, however distinct
mineral species were not actually described until the 1800s. Green tourmaline was
actually introduced in 1875 by George Kunz, an American mineral collector, from
the Mount Mica mine in Maine and sparked the popularity on the mainstream jewelry
market.
Schorl, dravite, uvite, liddicoatite and elbaite are the primary species of tourmaline.
Schorl is the most common variety, making up nearly 95% of all tourmaline deposits,
however not frequently it is desired as a gemstone. Chiefly the tourmaline gemstones
comes from of the elbaite family. As tourmaline possess a huge collection of correlated
gemstones, mainly tourmaline is traded under very color-specific varietal names.
Famous trade names of tourmaline are pink-red 'rubellite', blue-green 'Paraiba',
blue 'indicolite' and multicolored 'watermelon tourmaline'. Lesser-known trade names
include colorless 'achroite', green 'verdelite' and 'chrome tourmaline'. Descriptive
names for tourmaline such as 'yellow tourmaline' or 'pink tourmaline' are also commonly
used to market the fancy-colored tourmaline gemstones.
Properties - Tourmaline is famous in showing exclusive pyro-piezoelectric
characteristics that means crystals can produce and hold an electrical charge when
they are hold to mechanical stress, extreme temperature fluctuations or pressure,
earning it the nickname of the 'electric stone'. The rubbing of tourmaline crystals
cause static and when it is held over dust or ash. This static attracts particles,
which is why at times it referred as the 'Ceylonese (Sri Lankan) magnet'.
Availability - Tourmaline is available in pegmatites and alluvial
deposits across the globe. The United States was considered the primary source for
fine tourmaline. Currently important tourmaline deposits are from Minas Gerais and
Bahia, Brazil. Other prominent tourmaline sources are Afghanistan, Australia, Nigeria,
Malawi, Burma (Myanmar), Italy, (Elba) Madagascar, India, Mozambique, Namibia, Nepal,
Pakistan, Russia, Switzerland, (Tessin) Zaire, Tanzania, Sri Lanka, the United States
(California and Maine), Zambia and Zimbabwe.
Tanzania is popular in producing the fine emerald-green chrome dravite tourmaline,
in late 1990s, a copper-bearing blue Paraiba tourmaline was discovered in Nigeria;
soon, then, another deposit of a copper-bearing Paraiba tourmaline was found in
Mozambique. Africa's Paraiba tourmaline deposits were not brightly colored like
the Brazilian materials. Zambia is popular to have fine red rubellite and yellow
canary tourmaline, whereas Afghanistan is famous to have deposits of producing fine
green verdelite and rare blue indicolite
Buying Guide
Lately, tourmaline has become one of the famous color gemstones. Due to its wide
variety of colors new buyers are attracted by its huge choice of colors and its
very good gemstone characteristics -- it is practically hard as well durable enough
for every type of jewelry. It is an affordable gemstone.
Before you go to buy a tourmaline from the market it is better to read a guide and
know about the stone. So that you are able to buy a correct and that too in a right
amount.
In recent years tourmaline has become one of the most popular of all colored gemstones.
Due to the huge choice of colors the buyers new to tourmaline get attracted and
in fact a very good gemstone with properties like practically hard, and durable
enough for every type of jewelry. It is still a very reasonably priced gemstone
too, particularly in larger sizes, since per carat price for tourmaline doesn't
increase radically like the prices for larger sapphire and ruby.
However, there are some important differences between varieties of tourmaline, and
some colors are rarer and thus more expensive. This short buying guide will assist
you to know the quality and price grades in the current tourmaline market.
Tourmaline is one of the few gemstone where ranges of bi-color and tri-color specimens
is seen. These occur in all colors, but the most coveted color is the watermelon
tourmaline, known for its green and pink/red bands. Highest examples are greatly
regarded by collectors.
It is fair to describe that the famous tourmaline colors are green and pink. In
every shade of pink the tourmaline is available from the softest pink to intense
hot pink. The green tourmaline is known for the excellent clarity as well as a wide
variety of color from blue/green to forest green to mint. Green tourmaline is frequently
found in huge sizes at genuine cost.
Cut and Shape - Tourmaline is often cut into long rectangular bar
shapes because of its elongated crystal habit. However, the gemstone is also available
in various traditional and fancy shapes and a range of cutting styles. Because of
the strong pleochroism of tourmaline, lighter colored tourmaline is typically oriented
with the table facet perpendicular to the main axis, in order to present the richest
hue. However in general darker stones are usually cut with the table parallel to
the main axis. Watermelon tourmaline is often cut into slices to best exhibit its
characteristic and attractive color zoning.
Treatment - Tourmaline is very rarely treated. However, some stones
may be heated to improve color and clarity. Yellow, pink and red varieties of tourmaline
may be irradiated to enhance color, although irradiation is nearly impossible to
detect and does not normally affect value.
Gemological Characteristics: