mineral

Moonstone with Black Tourmaline

Orthoclase (KAlSi3O8) with Schorl inclusions (NaFe3Al6(BO3)3Si6O18(OH)4)

Hardness: 6-6.5 on Mohs scale; Color: Creamy white to pale yellow with black needle-like or blocky inclusions; Luster: Vitreous to pearly; Crystal structure: Monoclinic; Cleavage: Perfect in two directions.

Hardness: 6-6
Luster: Vitreous to pearly

Identified May 19, 2026More mineral →

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Physical properties

Formation & geological history

Formed in granitic and syenitic pegmatites through the slow cooling of magma. The Tourmaline inclusions crystallize alongside or within the feldspar matrix during the late stages of magmatic crystallization.

Uses & applications

Primarily used in jewelry (cabochons and beads), as tumbled stones for crystal healing practices, and as collector specimens.

Geological facts

Also sometimes marketed as 'Black Tourmaline in Feldspar' or 'Rainbow Moonstone' (if it shows adularescence, though technically that is Labradorite). The contrast between the light host and dark inclusions makes it a popular decorative stone.

Field identification & locations

Identify by the distinctive pearly luster of the feldspar host and the hard, black, non-metallic inclusions. Often found in India, Sri Lanka, and Madagascar.

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