Granite, Devon

Granite is formed when viscous (thick/ sticky) magma slowly cools and crystallises long before it is able to reach the Earth’s surface. Granite is a coarse-grained, crystalline rock, made up mostly of three minerals called quartz (grey, glassy looking), feldspar (usually white or pinkish, blocky shapes), and shiny black or pale mica.

Evidence from the radioactive elements they contain show that the granites of SW England cooled down about 300 million years ago.

Granite is a very resistant rock and weathers slowly to form thin soils with many large boulders sticking out - with typical tors forming the hill-tops as in the image below.