Certified Reference Materials
OU-6 Penrhyn Slate
Purchase Code: IAG CRM-1
IAG members: £ 100
Non-Members: £ 150
Certificate: OU-6 certificate
Geostandards and Geoanalytical Research, 29 (2) 237-239
OU-6 Penrhyn Slate was obtained from the Penrhyn Slate Quarries, Bethesda, North Wales, located in a north-south trending belt that cuts across part of Snowdonia. The slate is fine-grained, purplish grey, well-cleaved and of Cambrian age. The rock was originally deposited as a mud and was recrystallised during low grade metamorphism. Caledonian deformation aligned fine-grained mica in the rock to produce the slaty cleavage. The rock is mineralogically homogeneous on a fine scale, with the exception of occasional green reduction spots (Fe2+) and crystals of pyrite.
The material is available in units of 35 g packaged in a polyethylene sachet.