feldspars
31Myrmekite — describes a vermicular, or wormy, intergrowth of quartz in plagioclase. The intergrowths are microscopic in scale, typically with maximum dimensions less than 1 millimeter. The plagioclase is sodium rich, usually albite or oligoclase. These… …
32Pericline — also refers to a doubly plunging anticline or syncline. Pericline is a form of albite exhibiting elongate prismatic crystal. Pericline twinning is a type of crystal twinning which show fine parallel twin laminae typically found in the alkali… …
33Ceramic flux — A ceramic flux functions by promoting glass formation in clay bodies and glazes. Fluxes are used in glazes to lower the high melting point of silica. The most commonly used fluxes in a ceramic glaze are lead, boric, soda, potassium, lithium,… …
34Glossary of geology terms — Here is a glossary of Geological terms.A*Abyssal plain Flat or very gently sloping areas of the deep ocean basin floor. *Absolute dating the process of determining a specific date (in years or some other unit of time) for an archaeological,… …
35aluminum — aluminic /al yeuh min ik/, adj. /euh looh meuh neuhm/, n. 1. Chem. a silver white metallic element, light in weight, ductile, malleable, and not readily corroded or tarnished, occurring combined in nature in igneous rock, shale, clay, and most… …
36kaolinite — /kay euh leuh nuyt /, n. a very common mineral, hydrated aluminum disilicate, Al2Si2O5(OH)4, formed by the alteration of other minerals, esp. feldspar: the most common constituent of kaolin. [1865 70; KAOLIN + ITE1] * * * Group of common clay… …
37moonstone — /moohn stohn /, n. 1. Also called precious moonstone. a semitransparent or translucent, opalescent, pearly blue variety of adularia, used as a gem. 2. any of several adularescent feldspars, as certain varieties of albite, labradorite, or… …
38nepheline — /nef euh lin/, n. a feldspathoid mineral, essentially sodium aluminum silicate, NaAlSiO4, occurring in alkali rich volcanic rocks. Also, nephelite /nef euh luyt /. [1805 15; < F néphéline, equiv. to néphél ( < Gk nephéle cloud) + ine INE2] * * *… …
39colour index — In igneous petrology, the sum of the volume percentages of the coloured, or dark, minerals in the rock. The most common light coloured minerals are feldspars, feldspathoids, and silica or quartz; abundant dark coloured minerals include olivine,… …
40sedimentary rock — Rock formed at or near the Earth s surface by the accumulation and lithification of fragments of preexisting rocks or by precipitation from solution at normal surface temperatures. Sedimentary rocks can be formed only where sediments are… …
