Pyrope is an indicator mineral for high-pressure rocks.
It is an indicator mineral of the prehnite-pumpellyite metamorphic facies.
It is used as an indicator mineral in the search for diamonds.
They found kimberlitic indicator minerals near Lac de Gras in the Northwest Territories in 1985, and their first kimberlite at Point Lake in 1991.
Prospectors generally find diamond pipes the old-fashioned way: panning rivers and checking for diamonds or indicator minerals from pipes like garnets, pyrope and chromium diopside.
These indicator minerals are generally sought in stream sediments in modern alluvial material.
The island has been subject to diamond exploration following the discovery of a wide range of kimberlite indicator minerals there.
The Falconbridge-Superior joint venture then funded a research program by South African geochemist John Gurney, to study possible indicator minerals for diamondiferous pipes.
The presence of certain indicator minerals in the mixture suggested temperatures exceeded 250 C, a record for an underwater volcano.
There are the same indicator minerals for gold along with numerous silica blowouts, called jasperoids.