Question 1

What is the difference between pink tourmaline and rubellite?

Accepted Answer

Rubellite is a trade name for pink to red tourmaline with a strong, saturated colour that stays consistent under different light sources. Paler pinks are usually sold simply as pink tourmaline. There is no single agreed definition, and some laboratories use the term while others do not, so it is best to judge the colour of the stone itself rather than the name.

Question 2

What is chrome tourmaline?

Accepted Answer

Chrome tourmaline is an intense green tourmaline coloured by chromium, often with vanadium, rather than by iron as in most green tourmaline. It is usually dravite or uvite rather than elbaite and comes mainly from Tanzania and Kenya. It tends to be found in smaller sizes, and a laboratory can confirm the chromium content if the term is important to the buyer.

Question 3

Is tourmaline usually treated?

Accepted Answer

Many tourmalines are treated. Heat is used to lighten dark green and blue material, and irradiation is used to create or strengthen pink and red colour. Both treatments are stable and generally cannot be detected. Fracture filling is also found, particularly in pink and red stones. Untreated stones exist, but it is often impossible to prove that a tourmaline has not been heated or irradiated.

Question 4

What is bi-colour tourmaline?

Accepted Answer

Bi-colour tourmaline shows two distinct colours in one stone, most often pink and green. It is cut from crystals whose chemistry changed during growth, creating colour zones along the length. Watermelon tourmaline is a related type cut across the crystal, showing a pink core and green rim. Value depends on how sharply and evenly the colours are divided.

Tourmaline