Tourmaline Stone Beads
The
Tourmaline beads are made of such stones in which borosilicate
minerals are found. The different species and subcategories of
tourmaline beads are indicolite, achroite, rubbellite, schorl and
elbite. These beads are widely used in the jewelry industry, because
all positive characteristics are present in these beads. The
hardness of these beads is also significantly high and, therefore,
these beads are not fragile. The tourmaline beads comprise a wide
variety of colors, and only the black color tourmaline stone beads
are available in different black shades. Due to that extend of color
variations, these beads have given the name tourmaline, which means
rainbow. All the seven colors of the rainbow can be drawn with the
help of tourmaline stone beads and not any other stone beads. Tourmaline is a birthstone for October. In Western cultures, this stone representing the 8th wedding anniversary. To keep these stone beads in good condition, these should be protected from impact, harsh chemicals, excess temperature changing, high temperature, ultra-sonic cleaning, the relative hardness of these beads is in between of 7 to 7.5. the countries where tourmaline stones and tourmaline beads are available are Brazil, Sri Lanka, Italy, U.S.A and Pakistan.
Tourmaline Stone
Chemical Formula: (Na,Ca)(Mg,Li,Al,Fe2+)3Al6B3Si6(OH)4
Mineral Name: Tourmaline
Color: Varying shades of green, red, blue, yellow, brown, black etc
Hardness: 7 - 7.5
Specific Gravity: 3.03- 3.25
Tourmaline is a complex crystalline silicate containing aluminum, boron and other elements, used in electronic instrumentation and, especially in its green, clear, and blue varieties, as a gemstone. Its name has been derived from the Singhalese expression "tura mali" meaning stone of mixed colours. The name refers to the unique spectrum of colors displayed by this gemstone. Tourmalines are red and green, range from blue to yellow. There are Tourmalines, which change the color from daylight to artificial light and others display chattoyance.
Tourmaline is predominantly used as a jewelry stone, although it is also used in pipe cleaners (as in, the kind of pipes you smoke) due to it's piezoelectric properties which cause the soot to grasp on. It can be cut and polished a number of ways. Some tourmaline can exhibit a much-desired "cats-eye" effect when cut into a cabochon (sphere). Heat treatment of tourmaline can enhance the color. Some pink, green, and multicolored tourmalines are also carved into ornamental figures and carvings. Tourmaline is found in Africa, Brazil, Madagascar, Mexico, Myanmar, Namibia, Sri Lanka and USA.
Varieties of Tourmaline
» Elbaite - green variety of tourmaline (may also refer to multicolored tourmaline)
» Rubellite - pink to red variety of tourmaline
» Indicolite or Indigolite - light to dark blue variety of tourmaline
» Dravite - brown variety of tourmaline
» Achroite - colorless variety of tourmaline
» Schorl - black variety of tourmaline
» Watermelon tourmaline - tourmaline with a red center, surrounded by a green layer (or vice versa)
» Verdelite - name rarely used to describe green tourmaline
» Siberite - purple variety of tourmaline
» Paraiba tourmaline - neon-blue variety of tourmaline
Rubellite Tourmaline
Mineral Name: Tourmaline
Color: Red
Hardness: 7
Specific Gravity: 3.03- 3.25
Rubellite is a variety of tourmaline varying in color from a pale rose to a deep ruby, and containing lithium. Rubellite is the reddish pink to purple color variety of Tourmaline, the most varicolored of all gemstones. With its deep ruby red color, Rubellite is very rare and the most valuable form of Tourmaline. It consists of inclusions. The chemical impurities cause a growing crystal to become internally cracked- more the impurities, darker the shade of red.
Rubellite displays pleochroism i.e. the color changes when viewed at different angles but, this varies from specimen to specimen. It is supposed to be an especially powerful influence on love and friendship, lending to permanence and stability. It is faceted into gems for jewelry as well as carved into ornamental figures and carvings.
Green Tourmaline/Multicored Tourmaline/Elbaite
Mineral Name: Tourmaline
Color: Green
Hardness: 7
Specific Gravity: 3.0
The green Tourmaline, Verdelith or Elbaite is of fine emerald-like color caused by traces of chromium. Elbaite is the most colorful member of the group of tourmalines. It is cut as a gemstone, sliced into colorful cross-sections or simply appreciated as natural specimens by collectors. Elbaite contains many variety names based on color. A beautiful blue variety is called indicolite (also known as indigolite), the pink to red variety is called rubellite, the green variety is known as verdelite, while the most famous variety is a pink and green combination called watermelon tourmaline.
A specimen can have more than one color zone in the same crystal. Elbaite is strongly pleochroic, which means that a transparent crystal will appear darker when viewed down the long axis of the crystal.
Paraiba Tourmaline
Mineral Name: Tourmaline
Color: Yellow
Hardness: 7.5
Specific Gravity: 3.10 - 3.26
Paraiba Tourmaline is 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. The color is due to a small amount of copper and a little bit of gold.
Paraiba tourmaline is found in the federal state of Paraiba in the Northeast of Brazil. These stones are much coveted treasures when found in good quality.
Yellow Tourmaline
Mineral Name: Tourmaline
Color: Yellow
Hardness: 7
Specific Gravity: 3.03- 3.25
Most of the yellow tourmalines show a slightly brownish tinge. In the south of East Africa, in Malawi, gemstone occurrences containing beautiful yellow stones were discovered. These tourmalines were clear and pure and were named "Canary". The almost electric yellow color is caused by fine traces of magnesium. Since not all rough crystals show the brilliant yellow on being found, some of the stones need to be treated at circa 700 degrees celsius in an oven before they can be cut. The heating in such cases simply turns the second color, a slight brown, into the coveted bright yellow.
The yellow tourmalines are distinguished by their fine scent. On the place of their occurrence, Tourmaline crystals are often embedded into black material that need to be removed before the stones are cut. It was found that on boiling the rough crystals in water to which some lemon juice is added, the black material could be removed. And thus, yellow tourmalines from Malawi not only resemble fresh lemons in their pleasant color, but also in their fine scent.
Blue Tourmaline/Indicolite
Mineral Name: Tourmaline
Color: Blue
Hardness: 7.0 - 7.5
Blue tourmaline is supposed to be the most colorful and rare variety of all gemstones. It is sometimes referred to as "Indicolite". True blue Tourmalines are scarce as they show a more or less clearly pronounced shade of green. A blue Tourmaline emanates a high degree of harmony and are reported to bring about openness and tolerance. Indicolite is one of the rarer varieties of elbaite. It is transparent to opaque and is found in metosomatically-altered magnesian or dolomitic limestones in contact-metamorphic aureoles.
They are found in the classical Tourmaline country of Brazil, Namibia, Afghanistan, Pakistan and Nigeria. Having successfully passed the cutting procedure, Tourmaline proves a relatively robust stone. The gem cutter must be aware of this pleochroisim in order to maximize the color potential of the stone.
