Tri-colour tourmaline takes the colour banding seen in bi-colour crystals a step further, showing three distinct colour zones in a single crystal, typically progressing through combinations such as pink, colourless, and green.
Each colour band records a different stage in the crystal's growth. As the fluid the tourmaline crystallised from changed composition over time, often several times during a single crystal's formation, each shift left behind a new colour zone, effectively recording the crystal's own geological history in its banding.
Because it requires the growing conditions to change more than once, well formed tri-colour tourmaline is less common than simple bi-colour material, and Afghanistan remains one of the more reliable sources for well banded examples.
Tri-colour specimens are prized by mineral collectors specifically for the banding, since cutting the stone for jewellery often means sacrificing one of the colour zones.
See our Tri-Colour Tourmaline collection.