Tourmaline

About Tourmaline

No other gem species gives a designer this much to work with. Tourmaline grows in long prismatic crystals that can change color along their length or from core to rim, so a single crystal can yield a mint green stone, a raspberry pink stone, and a slice that shows both at once. Gemologists call the species a complex borosilicate; jewellers simply call it the most useful stone in the drawer.

The color comes from trace elements caught in the crystal as it grew — iron for the deep greens and blues, manganese for pinks and reds, and in the rare Paraiba material, copper. Because the chemistry shifts as the crystal forms, tourmaline is famous for zoning: bands and gradients that a good cutter orients deliberately rather than trying to hide.

At 7 to 7.5 on the Mohs scale, tourmaline is durable enough for daily wear in a ring, though the more included and heavily zoned pieces are better suited to pendants and earrings where they take fewer knocks. Tourmaline is strongly pleochroic, meaning it shows different colors down different crystal axes, so the cutter’s decision about orientation has as much to do with the finished color as the rough itself.

Why Sharon works with tourmaline

Sharon buys tourmaline rough and cut stones directly from cutters she has worked with for years, and she selects for color saturation and clean zoning rather than size. A great deal of her signature work — the watermelon slices, the mint-and-pink pairings, the long bar-set greens — starts with a tourmaline that came across her bench and suggested its own setting.

Caring for tourmaline

Clean tourmaline with warm water, mild soap and a soft brush. Avoid ultrasonic and steam cleaners, which can damage included or heavily zoned stones, and take rings off before heavy work.

Common questions about tourmaline