How to judge Tourmaline

TOURMALINE is a unique stone that presents itself in all the imaginable hues of the colour spectrum. Mainstream tourmalines are available in the various shades of red, green, blue and yellow. They may show two or more colours within a stone, and these colours can display nuances according to the light source.As such, no two tourmalines are alike. Colour is an important aspect of tourmaline. Proper lighting will enhance its colour, and each variety requires a different light source to show its colour to the best effect. Red, yellow and orange tourmaline, for instance, look bright under incandescent light, while the blue, green and violet varieties look vibrant under daylight.

Rubellite: This red variety simulates ruby colours in daylight and artificial light. If the colour changes with the source of light, the gem may be classified as pink tourmaline.

Green tourmaline: This variety is plentiful and comes in a wide range of shades. A deep green tone that may simulate fine emerald green is called ‘Chrome tourmaline’.

Indicolite: The blue variety of tourmaline, available in various shades of blue.

Paraiba tourmaline: Rare and the most expensive tourmaline, this is an intense deep blue to blue green variety from the mines of Paraiba in Brazil. Its blue far exceeds that of other gemstones.

Yellow tourmaline: A gem-quality variety from Malawi, found recently.

Black tourmaline: This variety is suitable for engravings and healing purposes.

Watermelon tourmaline: Has a pink core and green border, and is popular because of its unique but natural colour pattern.

Cat’s eye tourmaline: This variety is most often available in green, blue and pink.

Tourmaline has been found in significant quantities in Brazil (major source), United States, Russia, Pakistan, Afghanistan, Sri Lanka, Myanmar and Africa. Certain varieties tend to have more inclusions, like the reds and pinks, while blues, blue-greens and greens tend to be relatively clean. Tourmalines are cut differently according to their colour variances and crystal shapes. The stones may be cut rectangular or emerald shape to display the different colours. Lighter colour specimens may be cut round, oval, or fancy in different orientation. Prices vary depending on colour variety, size and quality.

Treatments and imitation: Tourmalines may be heat treated, irradiated or oiled to improve colour or clarity. The colours are usually stable under normal wear. Currently there are no synthetic tourmaline. The most frequently encountered imitations are man-made glass. All treatments should be disclosed at all levels of the distribution chain. If you are doubtful, consult a reputed gem testing laboratory.