Main Page | See live article | Alphabetical index Tephrite is an igneous, volcanic (extrusive) rock, of felsic composition, with aphanitic to porphyritic texture. Mineral assembly is usually abundant feldspatoids and plagioclase, and lesser alkali feldspar. Pyroxenes (clinopyroxenes) are common accessory minerals. Quartz and olivine are absent. See also: igneous rocks, list of rocks This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.