Perthite is used to describe an intergrowth of two feldspars: a host grain of potassium-rich alkali feldspar (near K-feldspar, KAlSi3O8, in composition)...

Sanidine is stable at the highest temperatures, and microcline at the lowest. Perthite is a typical texture in alkali feldspar, due to exsolution of contrasting...

with potassium. The resulting intergrowth of the two feldspars is called perthite. The higher-temperature polymorph of KAlSi3O8 is sanidine. Sanidine is...

Pahangite (also "Pahangese") Patna → Patnaites Penang → Penangite Perth → Perthites (also "Perthian" and "Perthling") Pullman → Pullmanites Putney → Putneyites...

"Dalmatian jasper" – not a jasper at all but a form of the igneous rock perthite. The black spots are composed of the rare amphibole arfvedsonite (and not...

charnockite series, consisting essentially of quartz, antiperthite (or perthite), orthopyroxene (usually hypersthene) and magnetite, and is equivalent...

Papagoite Pargasite Parisite Pectolite Larimar Pentlandite Peridot Periclase Perthite Petalite (castorite) Pezzottaite Phenakite Phlogopite Phosgenite Phosphophyllite...

commonly represented by orthoclase and the exsolved lamellar albite, form perthite. In some rocks the potash feldspar, in others the soda feldspar predominates...

composition alkali feldspars are allowed to cool slowly, exsolution occurs and a perthite structure results. Anorthoclase occurs in high temperature sodium rich...

occurs as fine parallel segregations alternating with pink microcline in perthite as a result of exolution on cooling. There are two variants of albite,...

feldspars. The feldspar has partly unmixed on the micro-scale to form a perthite, and the presence of the alternating alkali feldspar and plagioclase layers...

multiple twinning which forms a grating-like structure that is unmistakable. Perthite is either microcline or orthoclase with thin lamellae of exsolved albite...

intrusive rock, which consists essentially of alkali-feldspar (orthoclase, perthite, anorthoclase, and albite). Some samples may contain a small amount of...

layers will alternate between typically pink microcline, resulting in a perthite texture. Solid solution strengthening Abbaschian, Reza; Reed-Hill, Robert...

of plagioclase (lamellae) are present in potassium feldspar, is called perthite. The solid solution between anorthite and albite remains stable to lower...

as biotite granite: pink coarse-grained leucocratic; contains quartz, perthite, oligoclase, biotite and accessory apatite and zircon; veins of aplite...

Myrmekite replacing K-feldspar in perthite during Na-Ca-metasomatism, showing isolated quartz vermicules of irregular shape. Lyon Mountain granite gneiss...

Pescarese Pescarese Perth Perthert, Perthite, Perthian, Perthling, Perthonality, Pertho, Perthie Perthert, Perthite, Perthian, Perthling, Perthonality...

known as hypersthene). The alkali feldspars in the group are generally perthites, with intergrowths of albite and orthoclase or microcline, while the plagioclases...

Mount Desert Island bedrock consists mainly of Cadillac Mountain granite. Perthite gives the granite its pinkish color. The Silurian age granite ranges from...

feldspathoid minerals. In the acid rocks, the common feldspars are orthoclase, perthite, microcline, and oligoclase—all having much silica and alkalis. In the...

to coarse-grained and moderately foliated containing minerals such as perthite, quartz, hornblende with accessory biotite, opaques, apatite, and zircon...

form by exsolution are aids in interpreting cooling histories of rocks. Perthite is an intergrowth of K-feldspar with albite feldspar, formed by exsolution...

University of Chicago in 1948. His Ph.D. thesis was titled Petrogenesis of Perthite Pegmatites in the Btoch Hills, South Dakota. He received his D.Sc. in Geology...

syenite gneiss (mainly litchfieldite): nepheline, albite, microcline, perthite, dark green biotite, (calcite), (white mica), (zircon), (pyrochlore), (cancrinite)...

within the Concord complex is made up of coarse-grained phenocrysts of perthite that are surrounded by other various minerals such as: Plagioclase Microcline...

evidence of hydrothermal fluid alteration, including coarse-patch perthite, perthite crystals with albite rims, and the recrystallization of mafic minerals...

upper leg, above the other zones, and consists mainly of quartz, albite, perthite, and some muscovite. The second intermediate zone is located mostly below...

gives rise to multiple forms of unmixing products, e.g. various kinds of perthite. "Due to slow reaction kinetics, feldspars usually do not attain equilibrium...

Plagioclase displays zonation and albite twinning. Potassium feldspar can show perthite textures, carlsbad twinning, and, in microcline, tartan twinning. Quartz...