ZINKENITE
ZINKENITE Zinkenite – Pb9Sb22S42 – is a relatively rare sulfosalt that forms part of polymetallic Pb-Zn-Sb ores. It may contain Cu, Ag, Fe, and As. Zinkenite exhibits a very characteristic habit of fine prismatic crystals, which can be acicular to capillary, grouped in subparallel bundles. It can form fibrous to capillary aggregates with radial arrangement. […]
ZINNWALDITE
ZINNWALDITE Zinnwaldite is a name that was given to a dark lithium-bearing mica that occurs in a cassiterite-mineralized greisen in the locality of Cínovec (formerly “Zinnwald” = “tin forest”) in the Czech Republic, near the border with Germany. The name was discredited in 1998 and therefore zinnwaldite is no longer considered a mineral species, but […]
ZOISITE
ZOISITE Zoisite – (Ca2)(Al3)(Si2O7)(SiO4)O(OH) – is a rarer sorosilicate from the Epidote Supergroup, characteristic of some types of metamorphic rocks. It has no importance as an ore. Zoisite is the orthorhombic polymorph of clinozoisite. As impurities it may contain Ca, Na, Fe, Mn, Mg, Cr, Ti, V., Sr and H2O. There are four varieties: with […]
ZEOLITES
ZEOLITES Zeolites are a group of tectosilicates with just over 90 members whose structure is composed of SiO4 and AlO4 tetrahedra, with a (Si+Al)/O ratio equal to 1/2. What makes zeolites so industrially interesting is that, unlike most other tectosilicates, their structures have large vacancies, constituting very porous and permeable minerals, as the spaces are […]
ZINCITE
ZINCITE Zincite – ZnO – is a very rare oxide that was Zn ore in only one occurrence, in the Franklin Mining District (New Jersey, USA). New Jersey is a particular case, unique in the world, where a pre-Cambrian weathered Zn-Mn-Fe oxide and silicate deposit, hosted in marble, underwent metamorphism. Franklin and Sterling Hill mines, […]
ZIRCON
ZIRCON Zircon is a common nesosilicate that occurs as an accessory mineral in many types of rock. They are usually very small crystals. It is an ore of zirconium (“zirconite”) obtained from placers and, when in large crystals, can be used as a gemstone. It is important for geochronology, employing uranium isotopes. Zircon is part […]