Tourmaline
Tourmaline group
Uncommon · XY₃Z₆(T₆O₁₈)(BO₃)₃V₃W
A complex boron silicate with one of the widest compositional ranges of any mineral. Generates an electrical charge when compressed or heated due to its piezoelectric and pyroelectric properties. Bi-coloured crystals are common.
Identity
- Formula
- XY₃Z₆(T₆O₁₈)(BO₃)₃V₃W
- Chemical class
- Silicate
- Members
- Elbaite, Schorl, Dravite
- Mineral group
- Paraíba Tourmaline
- Also known as
- Rubellite (red to pink), Indicolite (blue), Verdelite (green), Paraíba tourmaline (copper-bearing, neon blue to green)
- Used in alchemy
- Tourmaline Powder
Crystallography
- Crystal system
- Trigonal
- Habits
- Prismatic, Columnar
- Fracture
- Conchoidal
Physical properties
- Mohs hardness
- 7.5
- Density
- 3.1 g/cm³
- Luster
- Vitreous
- Colors
- black, brown, green, blue, red, pink, yellow, colorless, multicolored
- Streak
- white
- Transparency
- Transparent, Translucent, Opaque
Geology
- Origins
- Igneous, Metamorphic, Hydrothermal
- Host rocks
- Granite, Schist and gneiss
- Associated minerals
- Quartz, feldspar, lepidolite, Beryl
- Found in
- Pegmatite, Pegmatite deposit
- Geography
- Brazil, Afghanistan, Pakistan, Madagascar, USA
Classification
- Rarity
- Uncommon
- Gem quality
- Yes
Arcane properties
- Affinity
- Arcane, Storm
- Effects
- Warding, Elemental lightning
- Planar origin
- Material Plane
Sources
- Tourmaline. Mindat.org (Hudson Institute of Mineralogy).
- M. Pasero and others, IMA Commission on New Minerals, Nomenclature and Classification, The New IMA List of Minerals, updated September 2026. International Mineralogical Association (CNMNC), 2026.
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Elbaite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Schorl. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- Elbaite. Mindat.org (Hudson Institute of Mineralogy).
- Tourmaline. Gemdat.org (Hudson Institute of Mineralogy).
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