mineral

Dyed blue-purple tumbled stone, likely quartz or calcite

Uncertain; commonly dyed quartzite/chalcedony (SiO₂) or calcite (CaCO₃)

AI-generated identification · may be incorrect

Smooth, highly polished, vivid violet-blue surfaces with cloudy internal texture; hardness is approximately 3 for calcite or 6.5–7 for quartz/chalcedony, with vitreous to waxy luster. No visible cleavage or crystal faces are present.

Identified August 15, 2026More mineral →

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At a glance

Common name: Dyed blue-purple tumbled stone, likely quartz or calcite
Scientific name: Uncertain; commonly dyed quartzite/chalcedony (SiO₂) or calcite (CaCO₃)
Category: mineral
Identified: August 15, 2026
Method: Standard

AI Estimated Value

Approximately $2–$15 each as common tumbled stones; perhaps $20–$50 if unusually large or sold as attractive polished specimens.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

The underlying stone formed naturally, but the intense uniform color strongly suggests human dyeing or coating after tumbling. Geological age and formation environment cannot be determined from the photograph.

Uses & applications

Used as inexpensive decorative stones, cabochons, jewelry, and craft material. Typical commercial value is low unless testing identifies a rarer natural material.

Geological facts

This appearance is often marketed misleadingly as “blue amethyst,” “dyed quartz,” or occasionally “cobalt calcite.” A streak test, hardness test, and acid reaction can distinguish likely materials, though these may damage the specimens.

Field identification & locations

Check for dye concentration in cracks or around edges, color rubbing under acetone, and bubbles or surface film indicating coating. Common sources include dyed Brazilian quartzite/chalcedony and dyed calcite from mineral markets.