Mineral description : Brookite

Brookite from Hardangervidda, Norway.
Seven pale brownish crystals rests on a matrix of albite. The biggest crystal is about 5mm.

Mineral class Oxides : Rutil Cassiterite group
Chemical formula TiO2
Crystal system Orthorombic
Habitus Tabular to lamellar, rhombic or dipyramidic crystals.
Cleavage Poor, fracture conchoidal, brittle.
Hardness 5.5 - 6
Density 4.1
Color Brownish to black crystals to almost colorless.
Streak Yellow to brownish.
Luster Adamantine to sub metallic, transparent to opaque.
Description  
Occurance  
Associates Quartz, adular, albite, anatase, titanite
Notes Named after the Brittish crystallograph H. J. Brooke.
Polymorph with rutile and Anatase.
Does not melt, infusible.
Unsolvable in acids.
Localities Sweden : rare but a few localities exists.
  • Alnön, Sundsvall, Medelpad. As small grains. (ref SGU Ba31, pg 267)
Norway :
  • Gamle grube, Strausheia. As a yellow mineral filling fractures in plagioclase.
  • Gjerdingen, Nordmarka. In druses.
  • Nedre Eiker. As pseudomorphs after titanite together with anatase.
  • Matskorhae, Hardangervidda. As reddish brown thin crystals, up to 5mm, together with rutile and anatase.
  • Hardangervidda. A number of localities are known in alpine veins. Often together with anatase, rutile and rock crystals.
  • Vetllia, Böverdalen, Lom. A single crystal is known.
Finland :
  • It's been found but I don't know where. If you know, please send me a mail.

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Last changed : 2000-12-27