mineral

Tumbled blue-purple stone, possibly lepidolite or dyed quartz

Tentatively lepidolite (lithium mica; K(Li,Al)₃(Si,Al)₄O₁₀(F,OH)₂), though the photograph is insufficient for confirmation

AI-generated identification · may be incorrect

Opaque to translucent blue-lavender, with a dull-to-waxy tumbled luster and irregular granular texture. Lepidolite is Mohs 2.5–3, micaceous, and has perfect basal cleavage; dyed quartz would be harder (Mohs 7) and lack obvious cleavage.

Identified August 18, 2026More mineral →

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Physical properties

Formation & geological history

Lepidolite forms in lithium-rich granite pegmatites during late-stage hydrothermal crystallization, commonly with tourmaline, quartz, and feldspar. Such pegmatites are generally Precambrian to Phanerozoic; a specimen’s age cannot be determined visually.

Uses & applications

Lepidolite is chiefly a lithium- and mica-bearing mineral and is popular in lapidary work and metaphysical collections. Tumbled pieces typically have modest commercial value.

Geological facts

Blue coloration is less typical of natural lepidolite, which is usually lilac, pink, or gray; vivid blue may indicate another mineral or dye. A hardness or streak test would substantially improve identification.

Field identification & locations

Common sources include Brazil, Madagascar, Zimbabwe, and the United States. Check for mica-like cleavage, a white streak, and softness; avoid scratching valuable material. Estimated value: $2–$15 for a small tumbled specimen.