mineral

Polished smoky quartz (likely iron-stained quartz)

Quartz, silicon dioxide (SiO₂); brown coloration may result from irradiation or iron-related staining/inclusions

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent brown to smoky-black color, vitreous luster, conchoidal fracture, hexagonal crystal structure, and no cleavage. The glossy surface indicates polishing or tumbling.

Identified September 1, 2026More mineral →

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At a glance

Common name: Polished smoky quartz (likely iron-stained quartz)
Scientific name: Quartz, silicon dioxide (SiO₂); brown coloration may result from irradiation or iron-related staining/inclusions
Category: mineral
Identified: September 1, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a small polished common piece; $30–$100+ for unusually transparent, attractive, or inclusion-rich 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

Hardness 7 Mohs; translucent brown to smoky-black color, vitreous luster, conchoidal fracture, hexagonal crystal structure, and no cleavage. The glossy surface indicates polishing or tumbling.

Formation & geological history

Quartz forms in hydrothermal veins, pegmatites, and cavities in igneous and metamorphic rocks; specimens may range from Precambrian to modern. Brown-red tones can reflect iron oxides or internal inclusions.

Uses & applications

Used as an ornamental and lapidary stone, carving material, and inexpensive jewelry or collector specimen; not typically used as aggregate in this polished form.

Geological facts

Quartz is one of Earth’s most abundant minerals and is chemically identical to clear rock crystal. Strongly transparent brown material is often sold as smoky quartz, while opaque iron-stained pieces may be marketed as brown quartz.

Field identification & locations

Identify by its glassy luster, hardness, lack of cleavage, and inability to scratch it with a steel knife; glass should not scratch it. Common sources include Brazil, Madagascar, the United States, Switzerland, and Spain.