Introduction: Quartz is one of the most abundant minerals in terrestrial crustal rocks. Viewed in planepolarized light with a petrographic microscope, quartz is clear (i.e., transparent). In cross-polarized light, quartz typically displays gray to white interference colors. Quartz (and other minerals) is deformed and transformed when subjected to strong shock waves, as a consequence of impact e...

OBJECTIVES To review the published literature on respirable quartz exposure and associated disease in agricultural related settings systematically and to describe personal respirable dust and quartz measurements collected on a sandy soil farm in the Free State province of South Africa. METHODS The published studies on exposure to respirable silica and quartz in agriculture and related setting...

Archean greenstone belts are renowned for their Au endowment. Gold can be associated with orogenic style of mineralization and diorite-hosted Au-Cu disseminated sulfides interpreted as a porphyry mineralization. The Regnault project, located in the Frotet–Evans belt (Superior craton), is structurally-controlled an unclear metallogenic model. aim this study to evaluate fertility granodiorite-dio...

The grade of a quartz ore is not a measure of its chemical reactivity. A high grade quartz sample (B) showed low reactivity in sodium silicate production. Structural imperfection usually occurs due to lattice defects in the quartz tetrahedron as a result of several substitutions that happen during mineralization. The random distortion of the quartz tetrahedron that could be affected by various ...

Three syenite dike sets, named the Santa Cruz dikes, are coeval with the 627 ± 13 Ma old porphyritic calc-alkalic Princesa Izabel granitoid, northeastern Brazil. Dike set 1 is up to 1.5 m wide, strike 030 e040 Az, roughly parallel to the regional foliation. Dike set 2 strikes 120 e130 Az and consists of xenolith-bearing syenites and is roughly parallel to dike set 3, which is up to 1.5 m wide a...

The large Bayanbaolege Ag polymetallic ore deposit is located in the Tuquan-Linxi Fe (Sn)-Cu-Pb-Zn-Ag-Nb (Ta) metallogenic belt, which an important part of Great Xing’an Range province, northeast China. sulfide–quartz vein-type orebodies are mainly hosted Cretaceous granodiorite porphyry and Late Permian Linxi formation. U-Pb dating zircon from post-ore diorite porphyrite yields age 124.8 ± 1.1...