Watermelon is a trade name given to tourmaline that shows a pink to red centre surrounded by a green outer zone, recalling the fruit in cross-section. On this page we gather the stones in our collection that carry this description, which in practice means bi-colour tourmaline — the only species in which this particular arrangement of colour occurs naturally.
The effect arises during crystal growth: as the chemistry of the fluid feeding the crystal changes, different trace elements are incorporated, with manganese generally responsible for the pink to red tones and iron for the greens. Because the zoning follows the crystal's growth structure, the way a stone is oriented and cut determines how the two colours present. Slices cut across the crystal show the classic concentric pattern most clearly, while faceted stones may place the boundary as a soft gradient or a defined line.
When choosing, weigh where the colour division sits, how evenly it is balanced, and how legible it remains face-up. Clarity and cut quality deserve equal attention, as tourmaline commonly carries growth tubes and inclusions that can affect brightness.
