Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a> (CC BY 2.0)
trigonaluncommonSilicates
Dravite
NaMg3Al6(BO3)3Si6O18(OH)4
Dravite typically forms prismatic crystals, often with a triangular cross-section and vertical striations, commonly appearing in shades of brown to black. It can also be found as transparent, gem-quality crystals in various colors.
Dravite Physical Properties
Mohs Hardness
7Crystal System
trigonalLuster
vitreousStreak Color
whiteCleavage
indistinct/poor basal, sometimes noneFracture
conchoidalSpecific Gravity
3.03Colors
brown, yellowish-brown, dark brown, black, green, blue, colorlessTransparency
transparentType Locality
Worldwide, notable localities include Austria, Brazil, Tanzania, Australia, Russia.Mineral Group
SilicatesUses
gemstone, collector's itemAssociated Minerals
quartz, feldspar, mica, calcite, garnetRarity
uncommonGeological Context
Dravite is a common tourmaline found primarily in metamorphic rocks such as schists and gneisses, and less frequently in pegmatites and hydrothermal veins. It forms under high-temperature and high-pressure conditions, often associated with boron-rich environments.
