The composition of garnet inclusions in natural garnets is exceptionally useful for identification of the chemical and physical properties of mantle lithologies in which they occur. The results of Raman study of garnet inclusions in Siberian diamonds are presented. Most of studied garnets belong to either peridotitic (P type, n = 101) or eclogitic (E type, n = 63), and some rare garnets are websteritic (n = 5). Detected spectroscopic features of garnets in diamonds reveal a wide wave number ranges for rotational R[SiO4], bending ν2, and stretching ν1 modes. The peak positions of the Raman bands correlate with content of major components of garnets. Raman shift of stretching ν1 and bending ν2 vibrations reflects Ca–Mg and Al–Cr isomorphism. The found correlations have been applied for rough estimation of the garnet compositions. This method allows to discriminate E‐type and P‐type garnets marking diamondiferous mantle rocks.

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The composition of clinopyroxenes is indicative for chemical and physical properties of mantle substrates. In this study, we present the results of Raman spectroscopy examination of clinopyroxene inclusions in natural diamonds (n = 51) and clinopyroxenes from mantle xenoliths of peridotites and eclogites from kimberlites (n = 28). The chemical composition of studied clinopyroxenes shows wide variations indicating their origin in different mantle lithologies. All clinopyroxenes have intense Raman modes corresponding to metal-oxygen translation (~300–500 cm−1), stretching vibrations of bridging O-Si-Obr (ν11~670 cm−1), and nonbridging atoms O-Si-Onbr (ν16~1000 cm−1). The peak position of the stretching vibration mode (ν11) for the studied clinopyroxenes varies in a wide range (23 cm−1) and generally correlates with their chemical composition and reflects the diopside-jadeite heterovalent isomorphism. These correlations may be used for rough estimation of these compounds using the non-destructive Raman spectroscopy technique.

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