silicates
Watermelon tourmaline
- Crystal system
- trigonal
- Hardness
- 7–7.5 on the Mohs scale
- Lustre
- vitreous
- Colour
- Pink core with a green rim
- Where it forms
- In lithium pegmatites where the chemistry of the residual fluid shifted during crystal growth.
- Chiefly from
- Minas Gerais, BrazilMaine, United StatesAfghanistanMadagascar
Why it is that colour
Zoned growth. The crystal began taking up manganese, giving pink, and later took up iron, giving green, as the composition of the surrounding fluid changed. Cut across the crystal, the change shows as concentric colour.
Safety
Safe to handle.
Where it comes from
Brazilian and Afghan material. Slices are commonly sold; well-formed ones are not cheap.
Historical use
None distinct from tourmaline generally.
Recorded as history and attributed where possible. That a stone was used for something establishes that people used it, not that it worked.
What is attributed to it, and since when
No traditional history. The name and everything attached to it are twentieth-century.
Described, not endorsed. Dating a claim is not the same as assessing it — but an association that first appears in a book published in 1985 is not an ancient inheritance, whatever the label says. A sincere account of feeling better is compatible with the stone doing nothing — see the placebo effect.
Worth knowing
A watermelon tourmaline is a growth record. The pink core formed first, from a fluid rich in manganese; the green rim formed later, after iron entered the system. Slice the crystal and you are looking at a cross-section through time, in the same way as a tree ring.
This is also why the stone cannot be assigned a single meaning even on the trade's own terms. If pink tourmaline means one thing and green another, a crystal that is both, in sequence, because the groundwater changed, is not obviously anything.
Identity checked against IMA-CNMNC master list, June 2025.