Tresayes Pegmatite
Introduction
The photograph on this page of Tresayes Pegmatite by Ashley Dace as part of the Geograph project.
The Geograph project started in 2005 with the aim of publishing, organising and preserving representative images for every square kilometre of Great Britain, Ireland and the Isle of Man.
There are currently over 7.5m images from over 14,400 individuals and you can help contribute to the project by visiting https://www.geograph.org.uk
Tresayes Pegmatite
Image: © Ashley Dace Taken: 26 Nov 2013
A pegmatite is a rock with abnormally large crystals. The Tresayes pegmatite has crystals up to 800 cm; these formed in the late upper vapour phase of the granite crystallisation. Large potassium-rich feldspars grew first before smaller feldspars, quartz and tourmaline grew in the interstitial space. The K-feldspars were mined for glass which requires aluminium, sodium and potassium.
Images are licensed for reuse under creativecommons.org/licenses/by-sa/2.0
Image Location
Latitude
50.39286
Longitude
-4.820928