Jeremejevite
Species
Legendary · Al₆B₅O₁₅(F,OH)₃
An aluminium borate first described in 1883 from Mt Soktui in Siberia. Gem crystals of cornflower blue came later from near Cape Cross and the Erongo Mountains in Namibia, but facetable material remains very rare. It forms late in granitic pegmatites.
Identity
- Formula
- Al₆B₅O₁₅(F,OH)₃
- Chemical class
- Borate
Crystallography
- Crystal system
- Hexagonal
- Habits
- Prismatic, Pyramidal
- Fracture
- Conchoidal
Physical properties
- Mohs hardness
- 6.5
- Density
- 3.28 g/cm³
- Luster
- Vitreous
- Colors
- sky blue, pale blue, colorless, pale yellow
- Streak
- white
- Transparency
- Transparent
Geology
- Origins
- Igneous
- Host rocks
- Granite
- Associated minerals
- Quartz, feldspar, Tourmaline
- Found in
- Pegmatite deposit
- Geography
- Namibia, Russia (Siberia), Tajikistan, Germany
Classification
- Rarity
- Legendary
- Gem quality
- Yes
Arcane properties
- Affinity
- Air, Light
- Effects
- Scrying, Mind
- Planar origin
- Material Plane
Sources
- 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, Jeremejevite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
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