orthoclase's Usage Examples:

In point of absolute mass they are insignificant compared with the abundance and variety of potassiferous silicates, which occur everywhere in the earth's crust; orthoclase (potash felspar) and potash mica may be quoted as prominent examples.

Moonstone is a mix of layers of albite and orthoclase.

Moonstone originates from the orthoclase feldspar mineral family.

Like the highlands of eastern Asia, those of Turkestan are mostly built up on Pre-Cambrian gneisses and metamorphic slates, resting upon granites, syenites, old orthoclase porphyries, and the like.

Teall has found to be a soda orthoclase.

Granite is a lighter colored igneous rock containing relatively large crystals of the minerals plagioclase, quartz and alkali feldspars such as orthoclase.

At upper right is a granite with the characteristic pinkish color given by orthoclase feldspar.

Thus, for instance, near Nikko in the upper valley of the Daiya-gawa, and in several other places in the neighboring mountains, a granite-porphyry appears with large, pale, flesh-colored crystals of orthoclase, dull triclinic feispar, quartz and hornblende.