Watermelon tourmaline
Variety Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH)
About it
Tourmaline with a pink core and a green rind, best seen in slices cut across the crystal. Brazil, Madagascar, and Maine are classic sources; slices are often polished and sold whole.
- Type
- Variety
- Group
- Elbaite variety (tourmaline)
- Formula
- Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH)
- Hardness (Mohs)
- 7–7.5
- Specific gravity
- 3–3.26
- Streak
- white
- Lustre
- vitreous (glassy)
- Crystal system
- Trigonal
- Colours
- pink centre, green rim
- Transparency
- transparent, translucent
- Cleavage and fracture
- poor; uneven to conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.