pigeonite

A micrograph of a twinned crystal of inverted pigeonite from a gabbro.
A micrograph showing a sample of inverted pigeonite from a slowly cooled gabbro. The augite lamellae here are relatively wide, separated from the enstatite host (magnified about 70.4×).
A micrograph showing a sample of inverted pigeonite from a slowly cooled gabbro. The augite lamellae here are relatively wide, separated from the enstatite host (magnified about 70.4×).

pigeonite, silicate mineral in the pyroxene family that occurs only in quickly chilled rocks, such as those formed from lava. It is an iron magnesium silicate considered to be intermediate between clinoenstatite and diopside. Inverted pigeonite (pigeonite with orthorhombic instead of monoclinic symmetry) commonly occurs in plutonic rocks, particularly gabbros. For detailed physical properties, see pyroxene (table).

This article was most recently revised and updated by John P. Rafferty.
Citation Information
Article Title: pigeonite
Website Name: Encyclopaedia Britannica
Publisher: Encyclopaedia Britannica, Inc.
Date Published: 07 December 2017
URL: https://www.britannica.comhttps://www.britannica.com/science/pigeonite
Access Date: November 21, 2024