Stöfflerite, (Ca,Na)(Si,Al)O8 in the Hollandite Structure: A New High-Pressure Polymorph of Anorthite from Martian Meteorite NWA 856

Document Type

Article

Publication Date

4-1-2021

Publication Title

American Mineralogist

Volume

106

Issue

4

First page number:

650

Last page number:

655

Abstract

We present the crystal structure, composition, and occurrence of stöfflerite, the naturally occurring Ca-aluminosilicate with hollandite-type structure. Stöfflerite is a high-pressure polymorph of anorthite and an approved mineral. The type material was found in the shergottitic martian meteorite Northwest Africa 856. Type stöflerite (Sto60Lin40) assumes space group I4/m with unit-cell dimensions a = 9.255(1) Å, c = 2.742(3) Å, V = 235.1(2) Å3, and Z = 2.

Keywords

High pressure; hollandite; new mineral; shock compression

Disciplines

Geology

Language

English

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