Massive, boudinaged, rose-coloured layers up to one metre in thickness composed of 60–80 vol% spessartine-rich garnet and 15–40 quartz occur high-pressure, garnet-mica schist on Margarita I...

in the asemi-gawa area of intermediate high-pressure and low-temperature sanbagawa metamorphic belt in central shikoku, japan, piemontite-quartz schists are common in which cation exchange between piemontite and garnet has been studied. piemontite in contact with garnet usually contains two zones in which core is enriched in mn3+ and surrounded by a rim rich in fe3+. garnet is ca-fe-bearing spe...

The Paleoproterozoic Lagoa do Riacho manganese deposit in the Borborema Province is central to unravelling genesis of deposits, redox evolution and genetic relationship West African Craton. With contents averaging 35 wt%, unit lithologically subdivided into oxidized silicate ores a garnetite (garnet-rich rocks) subgroup. ore consists mainly pyrolusite, manganese-oxyhydroxide spessartine. has rh...

Abstract Garnet, an important mineral component in Earth's interior, usually contains minor water as structural OH, but experimental data on OH incorporation the a function of chemical and thermodynamic parameters remain rare. In particular, role oxygen fugacity ( f O 2 ) that is variable Earth has not been well assessed. We examine effects at 1–3 GPa 800–1000°C, by H‐annealing gem‐quality spes...

Located at the eastern segment of Tethyan Himalayan tectonic unit, Cuonadong leucogranites (muscovite granite and pegmatite) have a mineral assemblage quartz, plagioclase, alkali feldspar, as well muscovite garnet. Garnets in both pegmatite belong to almandine–spessartine solid solution, with minor andradite, grossular, pyrope, show specific Mn zoning relatively rim-ward depletion trend. Howeve...

The equation of state (EoS) a natural almandine74spessartine13pyrope10grossular3 garnet typical composition found in metamorphic rocks Earth’s crust was obtained using single crystal synchrotron X-ray diffraction under isothermal room temperature compression. A third-order Birch-Murnaghan EoS fitted to P-V data and the results are compared with published for iron, manganese, magnesium, calcium ...

In the Asemi-gawa area of intermediate high-pressure and low-temperature Sanbagawa metamorphic belt in central Shikoku, Japan, piemontite-quartz schists are common in which cation exchange between piemontite and garnet has been studied. Piemontite in contact with garnet usually contains two zones in which core is enriched in Mn3+ and surrounded by a rim rich in Fe3+. Garnet is Ca-Fe-bearing spe...

Sector-zoned aegirine was found in a specimen of Sanbagawa quartz schist from the Iimori region of the western Kii Peninsula, central Japan. The schist consists of quartz, aegirine, albite, amphibole (magnesioriebeckite to manganocummingtonite), garnet (spessartine), rhodochrosite, pyrophanite, jacobsite, and apatite. Aegirine occurs as subhedral to euhedral prismatic crystals less than 250 μm ...

introduction the area of this study is located near hamadan within the sanandaj - sirjan tectonic zone. in the hamadan area, consisting mainly of mesozoic plutonic and metamorphic rocks, aplites and pegmatites locally contain garnets.(baharifar et al., 2004, amidi and majidi, 1977; torkian, 1995. garnet-bearing schists and hornfelses in the area are products of regional metamorphism shown by sl...