orthoclase feldspar
51Trachyte — is an igneous, volcanic rock with an aphanitic to porphyritic texture. The mineral assemblage consists of essential alkali feldspar; relatively minor plagioclase and quartz or a feldspathoid such as nepheline may also be present. (See the QAPF… …
52Geology of Jersey — The geology of Jersey is characterised by the Late Proterozoic Brioverian volcanics, the Cadomian Orogeny, and only small signs of later deposits from the Cambrian and Quaternary periods. The kind of rocks go from conglomerate to shale, volcanic …
53Essexite — (pronounced|ˈɛsəksaɪt), also called nepheline monzogabbro (IPA|/ˈnɛfəliːn ˌmɒnzoʊˈgæbroʊ/) is a dark gray or black holocrystalline plutonic igneous rock. Its name is derived from the type locality in Essex County, MA.Modern petrology identifies… …
54Felsic — is a term used in geology to refer to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. The term combines the words feldspar and silica. Felsic minerals are… …
55Moonstone (gemstone) — Moonstone General Category Feldspar variety Identification …
56Silicate minerals — ▪ Table Silicate minerals name colour lustre Mohs hardness specific gravity Tectosilicates (three dimensional networks) feldspar (for other examples, see feldspar) orthoclase flesh red, white to pale yellow, red, green vitreous 6–6½ 2.6… …
57Perthite — is used to describe an intergrowth of two feldspars: a host grain of potassium rich alkali feldspar (near K feldspar, KAlSi3O8, in composition) includes exsolved lamellae or irregular intergrowths of sodic alkali feldspar (near albite, NaAlSi3O8 …
58List of minerals — This is a List of minerals for which there are Wikipedia articles. Mineral variety names and mineraloids are to be listed after the valid minerals for each letter.For a complete listing (about 4,000) of all mineral names: List of minerals… …
59Zolanite — is the trademarked name distributed by the MRST Gemstone Cartel. Zolanite is a plagioclase feldspar [http://www.gia.edu/gemsandgemology/18578/1556/465/back issue article detail.cfm] exhibiting in certain directions a brilliant spangled appearance …
60Granulite — Granulites are fine to medium–grained metamorphic rocks that have experienced high temperatures of metamorphism, composed mainly of feldspars sometimes associated with quartz and anhydrous ferromagnesian minerals, with granoblastic texture and… …
