Norway

Nordland, Holandsfjord
┼gskardet

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)
Agskardet composition

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 ┼gskardet, Nordland.

Ertl A (2015) personal correspondence


last upgraded: 28-Jul-2015