Rock & Mineral Encyclopedia

Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.

Rainbow Moonstone

A near-colorless feldspar showing blue and multicolored sheen; gemologically a white labradorite rather than true orthoclase moonstone.

A pale green variety of feldspar moonstone showing a soft white or bluish adularescent sheen over a greenish body.

A smoky gray feldspar moonstone, often called new moon stone, showing a silvery-blue adularescent sheen over a translucent gray body.

A dark gray-to-black feldspar variety of moonstone that shows blue and white adularescent flash against a smoky body.

A common coarse-grained intrusive rock like granite but richer in plagioclase than potassium feldspar.

A dark, mafic potassic alkaline rock rich in augite with alkali feldspar and often nepheline, classically forming the base of layered sills.