Experimental modeling of the conditions of crystallization of subcalcium chromium pyropes

1062 Subcalcium chromium pyropes with a CaO concen� tration of ~3 wt % or lower and widely variable Cr2O3 concentration of ~5 wt % and higher are observed as inclusions in diamonds of peridotitic assemblage, xeno� liths of harzburgite (dunite) and lherzolite, and as indi� vidual grains in the heavy fraction of kimberlite [1–3]. Of special interest are chromium pyropes with a CaO concentration of