Rainbow Moonstone in Black Tourmaline
Plagioclase Feldspar var. Labradorite with Schorl inclusions · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Triclinic (Feldspar) and Trigonal (Tourmaline); massive granular habit in the matrix.
Mineral Group
Silicates (Tectosilicate for Feldspar; Cyclosilicate for Tourmaline)
Chemical Formula
(Na,Ca)(Al,Si)4O8 with NaFe3+3Al6(BO3)3Si6O18(OH)4
Formation Process
Igneous/Magmatic; forms during the late-stage crystallization of pegmatites via hydrothermal fluid interaction.
About This Crystal
A polished teardrop shape showing a milky white to translucent base with flashes of blue adularescence (blue glow) and heavy mottled inclusions of opaque black minerals.
Physical Characteristics
White to clear body with black spotting, white streak, perfect cleavage in two directions for feldspar, vitreous luster, specific gravity 2.56–2.67.
Optical Properties
Displays adularescence (a blue schiller effect caused by light scattering between microscopic layers of albite and orthoclase). Doubly refractive.
Hardness & Durability
Origin Region
Madagascar, India, and Sri Lanka; typically found in pegmatite formations.
Hardness & Durability
Mohs hardness 6.0 to 6.5. Brittle toughness; sensitive to pressure and thermal shock due to its cleavage planes.
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid ultrasonic cleaners, steam, or harsh chemicals. Store separately to prevent scratching.
Rarity & Value
Moderately common; value increases with the strength and coverage of the blue flash and the aesthetic distribution of black tourmaline contrast.
Special Characteristics
Features Labradorescence/Adularescence; the black inclusions are often fibrous or granular Schorl (Black Tourmaline).
Lore & History
Historically associated with lunar cycles and protection. In modern lore, it is believed to balance yin/yang energies and protect the aura through the combination of moonstone and tourmaline.