The eclogite was discovered in 1822 by René Just Haüy the french mineralogist, the name was given after the ancient greek word ’eklog’ (selection) + ’ite’ (french grammar element). The eclogite is a relatively rare but geologically significant metamorphic rock. Its two ’basic’ minerals are the green omphacite (pyroxene) and the reddish garnet (pyrope, almandine), but beside these it may consist quartz, kyanite, olivine, rutile, zoisite etc. The eclogite usually issues in more ten kilometers depth in high pressure usually from the transformation (metamorphism) of basalt. Rough grainy rock may indicate the presence of diamond. Localities: Russia, Canada, Norway, Greenland, Germany, Austria, Turkey, India etc.