Peridotite Slide

Welded tuff thin section slide exhibiting a jumbled mass of irregularly sized broken clasts held in situ by finer ash particles which have become welded together. This material was collected from Cumbria, the original rock is likely rhyolite, and indeed in hand specimen the tuff almost still looks like rhyolite and appears to show a form of banding.

Diorite thin section slide. Diorite is a grey to dark-grey intermediate intrusive igneous rock composed principally of plagioclase feldspar (typically andesine), biotite mica, hornblende, and/or pyroxene. This particular material was collected in Cumbria

Gabbro thin section exhibiting some of the textbook features one would expect from this coarse, mafic igneous rock. These slides supplement the hand specimens nicely and are useful for interpreting the crystalisation history of the rock.

Rhomb porphyry thin section exhibiting the textbook porphyritic texture of this rare igneous rock. The thin section shows a fine grained alkali feldspar groundmass with large phenocrysts of augite. This material was collected near Oslo in Norway.