A sample of eclogite from Almenning, Norway. Present are red-brown garnet, green omphacite, and white quartz.
Eclogite is a coarse- to medium-grained metamorphic rock consisting mainly of green pyroxene and red garnet. A very dense rock, it is formed deep in Earth's crust under conditions of very high temperature and pressure. It occurs in schists (Norway) and in diamond-bearing pipes of kimberlite (South Africa).