Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
trigonaluncommonSilicates
Tourmaline
(Na,Ca)(Li,Mg,Fe,Al)3Al6(BO3)3Si6O18(OH)4
This image displays a well-formed, prismatic tourmaline crystal exhibiting a vibrant pink to reddish hue, with characteristic striations along its length. The crystal appears transparent to translucent and is likely set on a matrix.
Tourmaline Physical Properties
Mohs Hardness
7Crystal System
trigonalLuster
vitreousStreak Color
whiteCleavage
indistinct/poor basalFracture
conchoidal to unevenSpecific Gravity
3.06Colors
pink, red, green, blue, yellow, brown, black, colorless, multi-coloredTransparency
transparentType Locality
Gaoligong Mts (Gaoligong Shan), Nujiang Autonomous Prefecture, Yunnan Province, ChinaMineral Group
SilicatesUses
jewelry, collector, pressure gaugesAssociated Minerals
quartz, feldspar, mica, beryl, topaz, lepidoliteRarity
uncommonGeological Context
Tourmaline is a complex borosilicate mineral that forms in a variety of igneous and metamorphic rocks, most notably in granitic pegmatites and hydrothermal veins. It can also be found in some metamorphic schists and gneisses.
