mineral

Milky Quartz or Moonstone

Silicon Dioxide (SiO2) or Potassium Aluminum Silicate (KAlSi3O8)

AI-generated identification · may be incorrect

Hardness: 6-7 Mohs scale, Color: Tan to light brown with cloudy translucence, Luster: Vitreous to pearly, Crystal structure: Trigonal or Monoclinic, Cleavage: None or imperfect

Identified June 2, 2026More mineral →

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Physical properties

Hardness: 6-7 Mohs scale, Color: Tan to light brown with cloudy translucence, Luster: Vitreous to pearly, Crystal structure: Trigonal or Monoclinic, Cleavage: None or imperfect

Formation & geological history

Quartz forms in igneous, metamorphic, and sedimentary environments; Moonstone specifically forms from sodium-rich and potassium-rich feldspar layers that intergrow causing light scattering (adularescence).

Uses & applications

Used frequently in jewelry as polished cabochons or tumbled stones, and as metaphysical or healing crystals.

Geological facts

This specimen displays tumble-polishing. If it is moonstone, the internal structure reflects light in a phenomenon called adularescence, which was once thought to be captured moonlight.

Field identification & locations

Identify by its cloudy translucence and waxy-to-vitreous feel. Commonly found in riverbeds as pebbles or in pegmatite deposits. Tumbled varieties like this are ubiquitous in crystal shops.