Search results
Results from the WOW.Com Content Network
A gabbroid typically has over 35% mafic minerals, mostly pyroxenes or olivine, while a dioritoid typically has less than 35% mafic minerals, which typically includes hornblende. [ 11 ] Gabbroids form a family of rock types similar to gabbro, such as monzogabbro , quartz gabbro , or nepheline-bearing gabbro .
Quartz gabbro is an intrusive rock with a composition intermediate between gabbro and tonalite.It is defined in the QAPF classification as coarse-grained igneous rock in which quartz makes up 5% to 20% of the QAPF mineral fraction, plagioclase makes up 90% or more of the total feldspar content, and the plagioclase is calcium-rich (%An > 50).
A dioritoid typically has less than 35% mafic minerals, typically including hornblende, while a gabbroid typically has over 35% mafic minerals, mostly pyroxenes or olivine. [9] The name diorite (from Ancient Greek διορίζειν , "to distinguish") was first applied to the rock by René Just Haüy [ 10 ] on account of its characteristic ...
Hornblende gabbro is an intrusive rock similar to normal gabbro (gabbro sensu stricto [1]).In the QAPF classification it falls within the gabbro field, in which quartz makes up 0% to 5% of the QAPF mineral fraction, plagioclase makes up 90% or more of the total feldspar content, and the plagioclase is calcium-rich (%An > 50).
Baddeleyite is a rare zirconium oxide mineral (ZrO 2 or zirconia), occurring in a variety of monoclinic prismatic crystal forms. It is transparent to translucent, has high indices of refraction, and ranges from colorless to yellow, green, and dark brown. See etymology below. Baddeleyite is a refractory mineral, with a melting point of 2700 °C.
Gneiss (/ n aɪ s / nice) is a common and widely distributed type of metamorphic rock.It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks.
This is a list of minerals which have Wikipedia articles. Minerals are distinguished by various chemical and physical properties.
Sample of norite Shocked norite found in the Taurus-Littrow valley on the moon during the Apollo 17 mission (sample 78236).. Norite is a mafic intrusive igneous rock composed largely of the calcium-rich plagioclase labradorite, orthopyroxene, and olivine.