GNEISS (SUPERB FOLDED EXAMPLE) - California

GNEISS

California

​​​​​​​​​​​​​​The geology of California is highly complex, with numerous mountain ranges. The oldest rocks are gneiss and schist, metamorphic rocks of Precambrian age. 

This is a superb folded example of gneiss with layers of pink orthoclase feldspar crystals and dark minerals such as hornblende. It has a natural flat base so that it stands upright for display.

Gneiss (pronounced 'nice') is formed under the extreme conditions that exist beneath mountain ranges and in the collision zone between continental plates. The very high temperatures and pressures enable the rock to change completely and new minerals to crystallise.