Pegmatites and Rare Minerals with Peter Vanstone

Wed, May 23, 2018: Pegmatites and Rare Minerals with Peter Vanstone

• Event Photos

Peter Vanstone provided the club with an detailed presentation about Pegmatites and Rare Earth Minerals and brought in many large and interesting examples of this type of igneous rock. 

Peter graduated from Lakehead University Geology and started as a project geologist throughout northern Manitoba and NW Ontario.  Moving to Tantalum Mining Corp. of Canada Ltd., in Lac du Bonnet, MB as a field and mine geologist and in the position of Chief Geologist for the last 10 years. Peter is currently a  consulting geologist to the minerals industry specializing in rare-element pegmatites (lithium, cesium, rubidium and tantalum).

• Peter Vanstone's Tanco Mine Report: ILSG #48, 2002 

• Handbook of Lithium 2004

Pegmatites are igneous (from magma, lava) rocks that cool and form crystals that are at least 1cm in diameter and contain rare minerals (see list above) along with gemstones (i.e. tourmaline, aquamarine, topaz, ....) . Because of processes including fractional crystallization the lava "pushes" ever so less dense minerals up or out to areas with less heat and pressure which allows the mix of minerals and super-heated fluids or melt (i.e. ionic minerals, water, CO2, chlorine ..) to cool slowly, align and form large crystals. Crystals of 5cm are common and the largest recorded are over 10m.

• GeologyLearn: Pegmatites

• Geology.com: Pegmatites

• A Collector's Guide to Maine Mineral Localities

• Granitic Pegmatites as Sources of Colored Gemstones

Attendance: 18