tourmaline can be found as an accessory mineral in a variety of rocks including leucogranite, pegmatite, quartz veins, and metamorphiccountry rocks in hajiabad-dehgah area in se of boroujerd city. tourmaline in pegmatites is coarse-grained, subhedral to euhedral, anddisplays strong to moderate pleochroic blue rimmed by olive green. in contrast, tourmalines from leucogranite, quartz-veins, and h...

Abstract This study describes mineralogical and crystallochemical characteristics of metamorphic tourmalines from an Alpine shear zone in a Variscan rock sequence the Maramures region northern part East Carpathians. We use this mineral to unravel aspects evolution tourmaline bearing host rocks compare crystallo-chemical other Alps. Petrographic microstructural observations, as well electron mic...

Geostatistical and multivariate statistical analyses were applied to heavy mineral data from an Amazonian fluvial-lake system near the Tapajós River mouth investigate spatial distribution source-area of sediments. Twenty-one points investigated, physical characteristics Green Lake deepest point determined. Sand accumulates in lake margins mud quantity increases towards center. Heavy assemblage ...

The origin of diamonds from Serra do Espinhaço in Diamantina region (State of Minas Gerais) and in Chapada Diamantina, Lençóis region (State of Bahia) remains uncertain, even taking into account the ample research carried out during the last decades. The lack of typical satellite minerals in both districts makes a kimberlitic source for these diamonds uncertain. In mid 18th century the occurren...

In the upper Subansiri District of Arunachal Pradesh, India, Higher Himalayan Crystallines are exposed in and around Taliha and the outcrop of MCT in the immediate south of Taliha is recognizable with the development of tourmaline bearing leucogranite dykes representing melting of the crustal rocks. The gneisses of the Taliha area consist of mainly quartz, mica, K-feldspar and garnet. The Quart...