Gehlenite Locality: Monzoni Mts, Fassa Valley, Trento Province , Trentino-Alto Adige , Italy ( Locality at mindat.org ) Size: miniature, 4.3 x 3.7 x 2.2 cm Gehlenite A nice miniature featuring sharp crystals of gehlenite to 6mm, from the type locality for this calcium aluminosilicate species. Ex. John White Collection. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Gehlenite
The aluminium-rich end-member of the melilite series — a calcium sorosilicate named for chemist Adolf Gehlen, first found in Italy's Monzoni Mountains.
Intro adapted from Wikipedia (CC BY-SA).
Gehlenite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₂Al(SiAl)O₇.
It crystallizes in the tetragonal crystal system (space group P-42_1m). It is a member of the Melilite structural group.
Key properties: Mohs hardness 5–6; specific gravity 3.038; White to grayish white streak; Vitreous to resinous luster; optically uniaxial.
IMA symbol Gh, grandfathered status — known before the IMA’s founding, named in 1815.
Found in contact metamorphosed impure limestones; in calcium-rich ultramafic volcanic rocks.
It is found associated with Dolomite, calcite, augite, olivine, nepheline, leucite, merwinite, spurrite, diopside, ferroan spinel, phlogopite, pyrope, grossular, antigorite, pyroxenes.
The name commemorates the German chemist, Adolf Ferdinand Gehlen (1775–1815). All rights reserved. No part of this publication may be reproduced.