Websterite

Websterite in the three-component diagram olivine-orthopyroxene-clinopyroxene

Banded websterite in a warehouse corridor in the McMurdo Dry Valleys, Antarctica

Websterites are relatively rare rocks from the group of ultramafic rocks . The content of clinopyroxene , orthopyroxene and olivine together is at least 90%, with the proportion of olivine in the mafic minerals not exceeding 10%. The rock thus belongs to the group of pyroxenites with a ratio of clinopyroxenes to orthopyroxenes of 1: 9 to 9: 1. Typical side effects are grenades and spinels . The rock was named after the town of Webster in North Carolina . Websterites occur mostly as cumulates in zoned ultrabasic complexes with peridotites .

Individual evidence

^ AJ Stoltz: Garnet websterites and associated ultramafic inclusions from a nepheline mugearite in the Walcha area, New South Wales, Australia. Mineralogical Magazine 48: 167-179 (1984).
^ Websterite at www.worldofstones.com

literature

Wolfhard Wimmenauer : Petrography of igneous and metamorphic rocks. Enke, Stuttgart 1985, p. 114. ISBN 3-432-94671-6

[1] AJ Stoltz: Garnet websterites and associated ultramafic inclusions from a nepheline mugearite in the Walcha area, New South Wales, Australia. Mineralogical Magazine 48: 167-179 (1984).

[2] Websterite at www.worldofstones.com