Boromullite
Boromullite is an IMA-recognized mineral species in the silicate class, with the chemical formula Al₉BSi₂O₁₉.
It crystallizes in the orthorhombic crystal system (space group Cmc2_1).
Key properties: specific gravity 3.081; optically biaxial.
IMA symbol Bmul, IMA status: approved, named in 2007.
Product of granulite facies metamorphism of boron-rich peletic rocks.
It is found associated with Sillimanite, werdingite, sekaninaite-cordierite, potassium feldspar, biotite, hercynite, ilmenite, ominelite-grandidierite, plagioclase, alusite, tourmaline.
Recognizes boron as an essential constituent and for its relationship to mullite.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet.
Browse more B minerals or help write this entry.