The Formation, genesis and exploration implication of garnet in Serpentinites of Bagh Borj (Kerman Province, Iran)

نوع مقاله : مقاله پژوهشی

نویسندگان

مرتضی رزم آرا فرزقی ¹

سمیرا عاقبتی ²

¹ دانشیار گوهر شناسی و کانی های صنعتی دانشگاه فردوسی مشهد

² دانشجوی کارشناسی ارشد، دانشگاه فردوسی مشهد

10.22067/gemiran.2026.48527

چکیده

Gem-quality transparent to semi-transparent crystals of demantoid from Bagh Borj, were examined by different conventional and advanced gemological methods. (XRD, EDXRF, XRF, Raman).
   This study focuses on garnets sourced from Bagh Borj (Kerman), using standard and advanced gemological methods as well as chemical analyses, XRD, energy dispersive X-ray fluorescence (EDXRF) and Raman spectroscopy.
   The results of XRF showed that the content of Cr and V in most samples is high, with some samples containing a Cr₂O₃ content up to 0.032%. This suggests that Cr is the primary chromogenic element of Bagh Borj area demantoid, but the role of vanadium cannot be ignored.
   Raman spectroscopy revealed absorption peaks near 868 cm^-1, 816 cm^-1 and 517 cm^-1, associated with (Si–O)_Str vibrations (Si–O stretching vibration), and absorption peaks are displayed near 358 cm^-1, related to the rotation of SiO₄–R(SiO₄)^4-, and the peaks near 517 cm^-1 are related to (Si–O)bend vibrations (Si–O bending vibration). Additionally, related absorption peaks near 164 cm^-1 are attributed to the translation of SiO₄–T(SiO₄)^4-, and absorption peaks near 226 cm^-1 are associated with the translation of X²⁺–T(X²⁺) (X²⁺ represents divalent ions).
   The high pressure mineral assemblage (amphibolite, garnet-amphibolite, kyanite-garnet-amphibolite, hornblendite and epidote-amphibolite), indicated that the studied garnet from serpentinite was formed through high pressure metamorphism, during the subduction zone serpentinization.

کلیدواژه‌ها

Bagh Borj area

demantoid garnet

inclusions

موضوعات

• گوهرشناسی و کانی های صنعتی

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