Norway
Color-zoned tourmalines are found in an elbaite-rich LCT-pegmatite. The
crystal studied has a pale pink interior that is fluor-elbaite, with a
dark yellowish rim which is fluor-liddicoatite grading to a Ca-rich
fluor-elbaite and a dark brown thin rim that is iron-rich. In one area
of the crystal, a 20 to 50 micrometer thick rim, there is a sodium-free
area corresponding to rossmanite as well as regions in thin veins that
are rossmanite.
Composition
The detailed composition has not been published at this time.
The approximate composition is close to:
[](Al2.5Li0.5)Al6(BO3)3[Si5(B,Al)O18](OH)3(OH)
References:
Kolitsch U, Andresen P, Husdal TA, Ertl A, Haugen A,
Ellingsen HV, Larsen AO (2013) Tourmaline-group minerals from Norway,
part II: Occurrences of luinaite-(OH) in Tvedalen, Larvik and
Porsgrunn, and fluor-liddicoatite, fluor-elbaite and fluor-schorl at
Ågskardet,
Nordland.
Ertl A (2015) personal correspondence
last upgraded: 28-Jul-2015