Rainbow Moonstone with Black Tourmaline

Physical Properties

Hardness: 6-6.5 (Moonstone) / 7 (Tourmaline); Color: White/Translucent with blue flash and black inclusions; Luster: Vitreous to pearly; Crystal structure: Triclinic; Specific Gravity: 2.6-2.7

Formation & Geological History

Formed in igneous and metamorphic rocks through high-temperature processes that allow Na and Ca feldspars to crystallize. The 'rainbow' effect is caused by light scattering between layers of albite and orthoclase.

Uses & Applications

Primarily used in jewelry, gemstone spheres, decorative ornaments, and by mineral collectors for its metaphysical properties and adularescence.

Geological Facts

Despite its common trade name, Rainbow Moonstone is technically a white variety of Labradorite feldspar rather than a true Orthoclase moonstone. The black inclusions are typically Schorl, the most common variety of tourmaline.

Field Identification & Locations

Identify by looking for the blue 'schiller' or adularescence effect when rotated under light. Often found in Sri Lanka, India, Madagascar, and Myanmar. Common in pegmatite deposits.

Identified on: 4/28/2026

Mode: Standard