Diamonds with inclusions are like little space capsules from the mantle: pristine mineral samples are protected by the diamond's indomitable embrace and transported to the surface by a volcanic rocket. Inclusions capture a picture of the rock and environment in which diamonds grow and indicate that garnet harzburgite (a type of peridotite) and eclogite are the most common rocks in which diamonds have grown.

A single mineral inclusion rarely defines a specific rock, but two or more minerals may enable interpretation of rock associations and origin. Some inclusion minerals are virtually unique to diamond sources and are thus sought in the exploration for diamonds. Click on any of the following pictures to zoom in on the image.

	A purple pyrope garnet, an indicator of garnet harzburgite, in a brownish diamond octahedron from the Udachnaya pipe, Sakha Republic, Russia (about 0.8 mm across).
	Orange "G5" garnet, typical of diamond eclogite, showing the conspicuous octahedral shape imposed by the enclosing diamond (about 0.5 mm across).
	Red chromian pyrope and green chromian diopside, indicators of a peridotite, in a diamond octahedron from the Mir pipe, Sakha Republic, Russia (each about 0.2 mm across).

Garnet and diopside photos: courtesy United Institute of Geology, Geophysics & Mineralogy (UIGGM), Siberian Branch of Russian Academy of Sciences, Novosibirsk.
Eclogite photo: Martin Prinz