orthoclase
1.A variety of transparent or translucent orthoclase.
2.A fine-grained, light-colored granitic rock consisting primarily of orthoclase and quartz.
3.An igneous rock composed chiefly of plagioclase and orthoclase, with small amounts of other minerals.
4.a transparent or translucent gemstone with a pearly luster; some specimens are orthoclase feldspar and others are plagioclase feldspar.
5.~(40)Ar-~(39)Ar DATINGS OF ORTHOCLASE AND MUSCOVITE FROM ALKALI-RICH PORPHYRIES IN THE BEIYA MINE, YUNNAN
6.A common, coarse-grained, light-colored, hard igneous rock consisting chiefly of quartz, orthoclase or microcline, and mica, used in monuments and for building.
7.40Ar-39Ar plateau dating of orthoclase from the syenite yielded an age of 27.14±0.05 Ma, which is slightly older than the age of its surrounding lava.
8.1.Under the pressure of 510MPa,the perthite in granite begin to disappear at 600℃,and under the700℃,most of them vanish and turn into orthoclase.
9.Comparing the infrared absorption spectra of the typical crystals of albite, orthoclase,nepheline of 4-coordinated Al~(3+) ions and spodumene, kyanite, beryl of 6-coordinated Al~(3+) ions with that of R_2O-Al_2O_3-SiO_2 system glasses, it has been found that in the glasses theAl~(3+) ions are 4-coordinated when R_2O/Al_2O_3>>1. But it is different in Li_2O-Al_2O_3-SiO_2glasses that the coordination number of part of Al~(3+) ions may be 6. No anomaly related to the presence of mixed alkali was found on the infrared andultra-violet absorption spectra for a series of alumino-silicate glasses.
