from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A mineral of the feldspar group, chiefly KAlSi3O8, used in making glass, porcelain, and enamel.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A common feldspar of igneous, plutonic, and metamorphic rocks, made of potassium aluminum silicate, with the chemical formula KAlSi3O8. Microcline is the main feldspar of granite. The bluish-green variety is called amazonstone, and is sometimes of gem quality. Used in ceramics, ceramic glazes, and as a scouring powder.
from the GNU version of the Collaborative International Dictionary of English
- n. A mineral of the feldspar group, like orthoclase or common feldspar in composition, but triclinic in form.
from The Century Dictionary and Cyclopedia
- n. A feldspar identical in composition with orthoclase, but belonging to the triclinic system.
Shimmering with dazzling soft lavender, violet or lilac luster to a deeper dark and mysterious purple with whirling patterns of black Augite, microcline feldspar lucid crystals tinged with orange Tinaksite describes the rare and recently discovered mineral gem Charoite.
The minerals included in this group are orthoclase, microcline, and the plagioclase feldspars.
(K2O · Al2O3 ·6SiO2), exists as minerals named orthoclase and microcline, melting at 1200°C.
Various mineral localities occur throughout the county, of which some of the most important occur on the shore at Portsoy, as for example the gabbro masses in Portsoy Bay with enstatite, hypersthene and labradorite, the graphic granite with microcline, muscovite and tourmaline at East Head, the chiastolite-schist west of the marble quarry, the mottled serpentine with strings of chrysotile.
The principal minerals are, plagioclase, biotite and microcline, with smaller quantities of quartz, iron oxide, pyroxene and garnet.
Plagioclase, microcline and quartz are the predominating minerals, while biotite, titanite, epidote, apatite, zircon and garnet are present in smaller quantities.
Radioactivity is continuous and mineralization is concentrated in the quartz-rich veins with accessory microcline, albite and zircon.
Perhaps 75\% of this is the plagioclase feldspars (mostly albite, oligoclase and labradorite) with the remainder as potassium feldspars (mostly microcline and orthoclase).