Tourmaline Guide

Tourmaline is the October birthstone and the 8th wedding anniversary gem.

Tourmaline has the widest range of colours apart from sapphire and spinel. The word ‘Tourmaline’ comes from Singhalese word “Turmali’ meaning gems of mixed colours. It has a superior hardness (7 to 7.5 on the Mohs scale). Tourmaline was first discovered in Brazil in the 1500s by a Spanish conquistador. Chinese Dowager Empress Tz’u Hsi (1835 – 1908) loved tourmaline and much of the tourmaline mined in San Diego, California was supplied to her and her court. In the 1980s, a new find of copper bearing elbaite tourmaline from Paraíba, Brazil came on to the market. The rare Paraiba tourmaline is prized for its neon blue/ green colours. More deposits have since been found in Nigeria and Mozambique. Paraiba Tourmalines prices have soared in recent years.

Physical Characteristics

COLOUR

Tourmaline is available in every colour, from colourless to black. It can show every tone from pastel to dark, and can exhibit various colours in the same stone. Intensity and saturation tend to be the most important factors. The more common darker olive tourmalines are much lower in price than fine green tourmaline or brighter bluish green tourmaline which at their best are transparent, brilliant, and clean. Every shade between green and blue exist from the green with a slight hint of blue to a blue with a slight hint of green to the true blue. Like green tourmaline the blue colours can be dark to light and strong and vivid or less saturated and grayish. While various warm to cool pinks are common, yellow and purple tourmaline are more rare.

Rubellite, a pink/red variety of tourmaline is one of the rarest and most sought-after of colours.

Paraíba tourmalines in neon blues and greens with their attractive hues, higher colour saturation, and great rarity are the most expensive.

CLARITY

Tourmaline is typically transparent to translucent. Tourmaline is often included. The level of inclusions can vary depending on the type of tourmaline, with some colours being more heavily included than others. Green tourmaline is often eye-clean, while blue, red and pink tourmaline, including rubellite, paraiba and watermelon tourmaline, are almost always found with significant inclusions. Cat’s eye tourmaline is usually translucent to opaque and owes its chatoyancy to thin needle-like inclusions.

CUT

Tourmaline comes in all shapes and sizes. It is often cut into long rectangular bar shapes because of its elongated crystal habit. However, tourmaline is also available in various traditional and fancy shapes and a range of cutting styles.

Tourmaline is strongly pleochroic, which means that it can show different colors when viewed at different angles, one of which is usually much darker than the other. Also many tourmaline gemstones absorb more light down the length of the crystal than across it. So a crystal that appears pale green across its length can be very dark green—sometimes almost black—when you look down its length. Cutters will orient the cut of rough tourmaline to achieve the most attractive hue.

Rare cat’s eye tourmaline is cut as a cabochon to best display the desirable cat’s eye chatoyancy.

Watermelon tourmaline is often cut into slices to best exhibit its characteristic and attractive colour zoning.

PYROELECTRICTY

Many tourmaline crystals exhibit polarity – the colour, electrical properties and the crystal forms are different at either end of the crystal. These variations arise because of the complex structure and chemistry of the stone. When heated or rubbed, it acquires an electric charge and attracts small objects like dust and other lightweight objects. This property, known as “pyroelectricity is why tourmaline is used in electrical devices to produce pressure gauges.
Spiritual & Health Benefits

Tourmaline is believed to help relieve stress, increase alertness, stimulate circulation, and boost the immune system. It is good for keeping the digestive system healthy, aiding detoxification and supporting weight loss, as well as strengthening teeth and bones.

It is also said to be helpful to artists, authors, actors and those in creative fields.
Care

Use warm soapy water and a soft cloth to clean your tourmaline jewellery. Be sure to rinse well to remove all soapy residue. As with most other gemstones, the use of ultrasonic cleaners and steam cleaners are not recommended.

Tourmaline is generally stable to light and isn’t affected by exposure to chemicals. Some tourmalines might have been treated to improve their colour. The two most important tourmaline treatments are heating and irradiation. Colour changes due to irradiation may fade with sustained exposure bright light or heat. High heat may alter the colour of tourmaline, and sudden temperature change (thermal shock) can cause fracturing.

Tourmaline can scratch other gems and also be easily scratched by harder gems such as sapphire and spinel so always store tourmaline jewellery separately.