Kyanite is one of the three Al2SiO5 polymorphs, the other two being andalusite and sillimanite. The three aluminum silicate polymorphs (kyanite, sillimanite, and andalusite) are of major importance in metamorphic and experimental... more
Kyanite is one of the three Al2SiO5 polymorphs, the other two being andalusite and sillimanite. The three aluminum silicate polymorphs (kyanite, sillimanite, and andalusite) are of major importance in metamorphic and experimental petrology because of their abundance in metamorphosed lutitic rocks and relatively simple chemistry. The crystal structure of kyanite sampled from crystalline schists of Sebeş-Lotru Series (Negovanu, Cibin Mountains, Romania) from Getic nappe of Southern Carpathians has been refined using X-Ray powder diffraction data and the Rietveld method. The Rietveld refinements were carried out using the computer program Diffrac plus TOPAS 4.1 (Bruker AXS GmbH). Pseudo-Voigt (pV) profile function was used for the fit of the peaks. Rietveld refinement using X-Ray powder diffraction data of kyanite sample in space group P-1 (No.2), a=7.1491Å, b=7.8792Å, c=5.5912Å, α=89.75º, β=101.16º, γ=105.92º, Z=4, confirm the basic kyanite structure.
The Trikorfo area (Thassos Island, Rhodope massif, Northern Greece) represents a unique mineralogical locality with Mn-rich minerals including kyanite, andalusite, garnet and epidote. Their vivid colors and large crystal size make them... more
The Trikorfo area (Thassos Island, Rhodope massif, Northern Greece) represents a unique mineralogical locality with Mn-rich minerals including kyanite, andalusite, garnet and epidote. Their vivid colors and large crystal size make them good indicators of gem-quality materials, although crystals found up to now are too fractured to be considered as marketable gems. The dominant lithology is represented by a garnet–kyanite–biotite–hematite–plagioclase ± staurolite ± sillimanite paragneiss. Thermodynamic Perple_X modeling indicates conditions of ca. 630–710 °C and 7.8–10.4 kbars. Post-metamorphic metasomatic silicate and calc-silicate (Mn-rich)-minerals are found within (i) green-red horizons with a mineralogical zonation from diopside, hornblende, epidote and grossular, (ii) mica schists containing spessartine, kyanite, andalusite and piemontite, and (iii) weakly deformed quartz-feldspar coarse-grained veins with kyanite at the interface with the metamorphic gneiss. The transition tow...
The Trikorfo area (Thassos Island, Rhodope massif, Northern Greece) represents a unique mineralogical locality with Mn-rich minerals including kyanite, andalusite, garnet and epidote. Their vivid colors and large crystal size make them... more
The Trikorfo area (Thassos Island, Rhodope massif, Northern Greece) represents a unique mineralogical locality with Mn-rich minerals including kyanite, andalusite, garnet and epidote. Their vivid colors and large crystal size make them good indicators of gem-quality materials, although crystals found up to now are too fractured to be considered as marketable gems. The dominant lithology is represented by a garnet–kyanite–biotite–hematite–plagioclase ± staurolite ± sillimanite paragneiss. Thermodynamic Perple_X modeling indicates conditions of ca. 630–710 °C and 7.8–10.4 kbars. Post-metamorphic metasomatic silicate and calc-silicate (Mn-rich)-minerals are found within (i) green-red horizons with a mineralogical zonation from diopside, hornblende, epidote and grossular, (ii) mica schists containing spessartine, kyanite, andalusite and piemontite, and (iii) weakly deformed quartz-feldspar coarse-grained veins with kyanite at the interface with the metamorphic gneiss. The transition tow...
