Search results
Results From The WOW.Com Content Network
Many of the minerals of these rocks are schillerized, as they contain minute platy or rod-shaped inclusions, disposed parallel to certain crystallographic planes or axes. The reflection of light from the surfaces of these inclusions gives the minerals often a peculiar appearance, e.g. the quartz is blue and opalescent, the feldspar has a milky ...
Topaz on matrix from Dassu in Gilgit Baltistan Brookite and Quartz mineral from Balochistan. Gemstones, also known as semi-precious stones or gems, are minerals widely used in jewelry and for ornamental purposes. Northern and western regions of Pakistan are rich in high quality gemstones.
In 2013, analytical tests by the Curiosity rover found results consistent with the presence of smectite clay minerals on the planet Mars. [22] [23] [24] Illite group which includes the clay-micas. Illite is the only common mineral in this group. [21] Chlorite group includes a wide variety of similar minerals with considerable chemical variation ...
Minerals in soils are found in two types; primary and secondary. [5] "A primary mineral has not been altered chemically since its crystallization from a cooling magma." [5] Additionally, a primary mineral is defined as a mineral that is found in soil but not formed in soil, whereas secondary minerals are formed during weathering of
Iron oxide copper gold (IOCG) deposits are considered to be metasomatic expressions of large crustal-scale alteration events driven by intrusive activity. The deposit type was first recognised by discovery and study of the supergiant Olympic Dam copper-gold-uranium deposit (Olympic Dam mine), and South American examples.
Molybdenite is a mineral of molybdenum disulfide, Mo S 2. Similar in appearance and feel to graphite , molybdenite has a lubricating effect that is a consequence of its layered structure. The atomic structure consists of a sheet of molybdenum atoms sandwiched between sheets of sulfur atoms.
High-grade gold ore from the Harvard Mine, Jamestown, California, a wide quartz-gold vein in California's Mother Lode. Specimen is 3.2 cm (1.3 in) wide. Various theories of ore genesis explain how the various types of mineral deposits form within Earth's crust. Ore-genesis theories vary depending on the mineral or commodity examined.
The name comes from the green hue imparted by the colour of the metamorphic minerals within the mafic rocks: The typical green minerals are chlorite, actinolite, and other green amphiboles. Greenstone belts also often contain ore deposits of gold , silver , copper , zinc , and lead .