Tourmalines
are precious stones displaying a unique splendour of colours. According to an
ancient Egyptian legend this is the result of the fact that on the long way
from the Earth’s heart up towards the sun, Tourmaline travelled along a
rainbow. And on its way it collected all the colours of the rainbow. This is
why nowadays it is called the "Rainbow gemstone”.
However, the name "Tourmaline” has been derived from
the Singhalese expression "tura mali”, which translates as "stone of
mixed colours.” The very name already refers to the unique spectrum of colours
displayed by this gemstone, which is second to none in the realm of precious
stones. Tourmalines are red
and green,
range from blue
to yellow.
Often they show two or more colours and are cherished for this parti-
or multi-coloured appearance. There are Tourmalines which change their
colour from daylight to artificial light, others display chattoyance. No
Tourmaline exactly resembles another one: this gemstone shows many faces and is
thus excellently suited to match all moods and tempers. It does not come as a
surprise, then, that ever since ancient days it has been attributed with
magical powers. Tourmaline is supposed to be an especially powerful influence on
love and friendship, lending them permanence and stability.
Colours,
Names and Nicknames
In order to understand this multitude of colours you will
have to polish up your knowledge of gemmology: Tourmalines are mixed crystals
of complex aluminium-borosilicate varying in their composition. The slightest
changes in composition will result in completely different colours. In fact,
crystals showing one colour only are quite rare; generally one and the same
crystal displays several shades and colours. Not only the wide range of colours
characterises this gemstone, it also shows a remarkable dichroism. Depending on
the angle of view the colour will be different or at least show different intensity.
The deepest colour always appears along the main axis, a fact that the gemstone
cutter has to keep in mind when cutting the stone. This gemstone is excellently
suited for wearing and is uncomplicated to care for, since all Tourmalines show
a hardness of 7 to 7.5 on the Mohs’ scale. Thus Tourmaline is an interesting
gemstone in many aspects indeed.
The different
shades of colour have been assigned different names in the trade. For example,
deep red Tourmaline is named "Rubellite”,
provided it shows the same fine ruby-red shade in daylight and in artificial
light. Should the colour change when the source of light changes, the stone
will be called a "Pink Tourmaline”. Blue Tourmalines are called
"Indigolith”, "Dravite” is a golden-brown to dark brown Tourmaline,
and black Tourmalines are known as "Schorl”. The latter stone is mainly
used for engravings and in esotericism, where it is highly cherished because it
is reputed to ward off harmful radiation from its wearer.
Very popular is "Verdelith”, the green
Tourmaline, however, if its fine emerald-like green is caused by traces
of chromium, the stone is named "Chromium-Tourmaline.” But the outstanding
highlight among Tourmalines is of course Paraiba
Tourmaline, a gemstone showing a vivid deep blue to bluish green, found
for the first time in1987 in the mines of the Brazilian state of Paraiba. In
good qualities these stones are much coveted treasures. Since yellow
Tourmalines from Malawi of brilliant colour have been offered on the
market, the formerly missing colour yellow has been added in excellent quality
to the apparently unlimited range of colours shown by the "Rainbow
Gemstone.”
These are by no means all the names Tourmaline has
achieved: there still have to be mentioned bi-coloured and multi-coloured
Tourmalines Very popular are also slices cut as cross-sections through
Tourmalines, as these will render the full splendour of colours embedded in a
specific Tourmaline. For example, such slices taken from Tourmalines with red
heart and green border are called a "Watermelon-Tourmaline”; slices with a
clear heart and a black border are called "Moor’s head –Tourmaline”
Tourmalines are mined everywhere in the world. There are
important occurrences in Brazil, in Sri Lanka and South and Southwest Africa.
Other occurrences are situated in Nigeria, Zimbabwe, Kenya, Tanzania,
Mozambique and Madagascar, Pakistan and Afghanistan. Tourmalines are also found
in the USA, first of all in Maine and Utah. But although there are rich
occurrences of Tourmalines all over the world, good qualities and fine colours
are only rarely offered on the market. Therefore, then, the price range
achieved by Tourmaline almost matches its wide range of colours.
The
"Ashes-Extractor"
Not only
designers are fascinated by Tourmaline because of its incomparable wealth of
colours providing unlimited inspiration. Scientists are also intrigued due to
its astonishing physical characteristics: by heating and subsequently cooling
down Tourmalines will be charged up. The stone will then show positive charge
at one end, and negative charge at the opposite pole. This is termed
"pyro-electricity”, according to the Greek word "pyros" denoting
fire. Pressure will also lead to the stone’s charging, and in the course of
discharging the plus- and minus-poles will alternate, so that the stone will
show vibrations similar to Rock Crystal, but much stronger. The Dutch, who
originally brought Tourmaline to Europe, already knew about this effect long
before it was subjected to scientific study. They used heated Tourmalines to
extract the ashes from their meerschaum pipes and named the gemstone
"Aschetrekker”.
Tourmaline is a very special stone indeed and holds an
outstanding position in the fascinating world of gemstones. Its excellent
availability and unique splendour of colours make it one of the most popular
gemstones – and besides almost every Tourmaline is an original.