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Tourmaline

Multi-Color Variety | Tourmaline

Twilight's sun beyond the horizon explodes the sky with scattered and reflected sunlight, illuminating the world with a medley of colors. From dusk til dawn, the rainbow hues and tones of the in-between hours can be matched to examples of tourmaline, nature's kaleidoscopic gemstone. Tourmaline's enchantment lies in its treasure trove of tinted choices, having been found in most every hue known to man. Reds, greens, blues, and pinks sit next to examples of purple, orange, yellow, colorless, and even black tourmaline. A true joy to the collector, its finest cannot be pegged to one specific color or combination, but instead brings joy and marvel from many levels.

 

Tourmaline is the term given to a select group of minerals that have nearly identical crystal structure, but which hold slight differences in their chemical composition. Most gem examples are elbaites (Na(Li,Al)3Al6(BO3)3Si6O18(OH)4 ) with a concoction of other contained elements, such as calcium, magnesium, titanium, copper, and more. These elemental brews allow tourmaline to show complex arrangements of color, often seen in bi-colored and parti-colored crystals. Their crystalline formations can be so dramatic that their value as a mineral specimen would outweigh the want of turning it into a faceted gem, creating two demanding markets for the already rare stone.

 

Tourmaline has been known to man for centuries, even though its gemological properties and classification has only been recorded within the last few hundred years. High jewels assumed to have been set with rubies and emeralds have been found to hold remarkable tourmalines instead. The name tourmaline was given after the Sinhalese word, “tourmali”, meaning mixed parcel, an ode to the arrangement of color often seen. Tourmaline is typically found in areas with heavy pegmatite formation, making Brazil, Mozambique, Madagascar, Nigeria, Kenya, Malawi, the United States, and others being important sources of the gem.

 

Ranking a 7.0 - 7.5 on the Mohs scale of mineral hardness, tourmaline is well suited for use in jewelry for personal adornment. Sharing with opal, tourmaline is the birthstone of those among us born in October, and the gemstone of those under the zodiac sign of Leo. A strongly pleochroic and doubly refractive gem, tourmalines must be expertly cut to display its most desirable color. While many tourmalines go untreated, heating and irradiation is commonly employed to lighten and intensify a few colors. Fine gems of vivid saturation and uncommon hues make tourmaline's reign on the spectrum seem endless.

Specifications

Hardness :

7-7.5

RI :

1.624 to 1.644

SG :

3.06 (+0.20, -0.06)

Gem DNA :

Elbaite Na(Li1.5,Al1.5)Al6Si6O18(BO3)3(OH)4
Dravite NaMg3Al6Si6O18(BO3)3(OH)4
Liddicoatite Ca(Li2Al)Al6Si6O18(BO3)3(OH)3F
Chromedravite NaMg3Cr6Si6O18(BO3)3(OH)4


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