Mineral Factbook

Watermelon tourmaline

Varietyof Elbaite

Watermelon tourmaline is elbaite tourmaline with a pink core and green rim. As a variety of Elbaite, it shares that species' composition (Na(Al1.5Li1.5)Al6(Si6O18)(BO3)3(OH)3(OH)), crystal structure, and hardness; the distinction is the appearance defined above.

About Elbaite

Full reference data — crystallography, X-ray diffraction, and cited physical properties — is on the Elbaite species page.

FormulaNa(Al1.5Li1.5)Al6(Si6O18)(BO3)3(OH)3(OH)
Density (calculated)3.152
Crystal systemtrigonal
Streakwhite