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Tourmaline mineral

Adachiite

All data from the card 12
Category
Tourmaline Group
Formula
CaFe3Al6(Si5AlO18)(BO3)3(OH)3(OH)
IMA symbol
Adc
Strunz classification
9.CK.
Crystal system
Trigonal
Crystal class
3m - Ditrigonal Pyramidal
Unit cell
1578.39 ų
Color
Brownish–purple to bluish–purple
Specific gravity
3.228
Density
3.228 g/cm3
Birefringence
δ = 0.030
Pleochroism
Strong

Adachiite (CaFe3Al6(Si5AlO18)(BO3)3(OH)3(OH)) is a brownish–purple to bluish–purple mineral, discovered in 2013 and described in 2014.

It is named for Tomio Adachi, an amateur geologist and retired teacher who performed many investigations in and around the Kiura Mine and inspiration to many local children who would go on to become professional mineralogists.

Its type locality is the Kiura Mine in Ōita Prefecture, Japan.

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