glassy feldspar — Sanidine San i*dine, n. [Gr. ?. ?, a board. So called in allusion to the tabular crystals.] (Min.) A variety of orthoclase feldspar common in certain eruptive rocks, as trachyte; called also {glassy feldspar}. [1913 Webster] … The Collaborative International Dictionary of English
glassy feldspar — noun : sanidine … Useful english dictionary
Glassy — Glass y, a. 1. Made of glass; vitreous; as, a glassy substance. Bacon. [1913 Webster] 2. Resembling glass in its properties, as in smoothness, brittleness, or transparency; as, a glassy stream; a glassy surface; the glassy deep. [1913 Webster] 3 … The Collaborative International Dictionary of English
feldspar — [feld′spär΄] n. [altered < Ger feldspath (now feldspat) < feld, FIELD + spath, spar < IE base * spe , long, flat board > SPOON, SPADE1] any of several light colored, hard, glassy, monoclinic or triclinic minerals made up of aluminum… … English World dictionary
feldspar — /feld spahr , fel /, n. any of a group of minerals, principally aluminosilicates of potassium, sodium, and calcium, characterized by two cleavages at nearly right angles: one of the most important constituents of igneous rocks. Also, felspar.… … Universalium
alkali feldspar — Any of several common silicate minerals that often occur as whitish to variously coloured, glassy crystals. The alkali feldspars may be regarded as mixtures of sodium aluminosilicate (NaAlSi3O8) and potassium aluminosilicate (KAlSi3O8). Both the… … Universalium
Sanidine — San i*dine, n. [Gr. ?. ?, a board. So called in allusion to the tabular crystals.] (Min.) A variety of orthoclase feldspar common in certain eruptive rocks, as trachyte; called also {glassy feldspar}. [1913 Webster] … The Collaborative International Dictionary of English
igneous rock — Any of various crystalline or glassy, noncrystalline rocks formed by the cooling and solidification of molten earth material (magma). Igneous rocks comprise one of the three principal classes of rocks, the others being metamorphic and sedimentary … Universalium
Tachylite — (also spelled tachylyte) is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt. It is a basic type of igneous rock that is decomposable by acids and readily fusible. The color is a… … Wikipedia
Spherulite — Spherulites, in petrology, are small, rounded bodies that commonly occur in vitreous igneous rocks. They are often visible in specimens of obsidian, pitchstone and rhyolite as globules about the size of millet seed or rice grain, with a duller… … Wikipedia
