The ultramafic igneous rock, harzburgite, is a variety of peridotite consisting mostly of the two minerals, olivine and low-calcium (Ca) pyroxene (enstatite); it is named for occurrences in the Harz Mountains of Germany. It commonly contains a few percent chromium-rich spinel as an accessory mineral. Garnet-bearing harzburgite is much less common,... Found on http://en.wikipedia.org/wiki/Harzburgite