Ultrahigh-Pressure Metamorphic Graphite and Diamond

From the Kokchetav Massif, Northern Kazakhstan

A very interesting occurrence of graphite occurs with diamond in the ultra-high pressure metamorphic rocks of the diamond-bearing garnet-clinopyroxene rocks and clinozoisite gneisses at the Kumdy-Kol and Barchi-Kol microdiamond deposits. The graphite occurs in a variety of morphologies, including well-crystallized tabular or columnar crystals, and spheroidal aggregates sometimes enclosing microdiamonds. Information and images on these pages are provided courtesy of Dr. Andrey Korsakov, Institute of Mineralogy and Petrography, Russian Academy of Sciences, Novosibirsk, Russia.


Click on the map for a larger map with geological details.


Scanning electron microscope (SEM) images of a diamond crystal (not visible) completely overgrown by highly crystalline graphite from garnet-clinopyroxene rocks from the Kokchetav massif (for detailed mineralogy and petrology see Korsakov and Hermann 2006). (Click on any image to see a higher resolution image.)


(a) Overall view of graphite coated diamond. 
(b-c) Enlargement showing a large euhedral graphite crystal connected only by a narrow neck to "main" aggregates.


(d-f) Details of the surface morphology of graphite crystals presented in (b-c).


(g-l) Overall view and details of growth layers on a euhedral graphite crystal from the graphite coating.




Andrey V. Korsakov, Karel Theunissen and Larissa V. Smirnova (2004) Intergranular diamonds derived from partial melting

of crustal rocks at ultrahigh-pressure metamorphic conditions. Terra Nova 16, 146-151.


Andrey V. Korsakov and Jörg Hermann (2006) Silicate and carbonate melt inclusions associated with diamonds in deeply subducted carbonate rocks. Earth and Planetary Science Letters 241, 104-118.


A.V. Korsakov, K. Theunissen, O.A. Kozmenko, and Yu.I. Ovchinnikov (2006) Reaction textures in clinozoisite gneisses. Russian Geology and Geophysics [Geologiya i Geofizika]

47(4), 499-512.

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