mineral

Quartz–calcite sulfide-bearing mineral specimen

Quartz (SiO₂) with likely calcite (CaCO₃) and iron sulfides, possibly pyrite (FeS₂); exact species requires testing

AI-generated identification · may be incorrect

White druzy quartz and pale translucent calcite crystals coat a gray metallic matrix with brassy grains and reddish iron-oxide staining. Quartz hardness 7, vitreous luster; calcite hardness 3 with rhombohedral cleavage and effervescence in dilute acid; pyrite hardness 6–6.5, metallic luster.

Identified August 23, 2026More mineral →

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At a glance

Common name: Quartz–calcite sulfide-bearing mineral specimen
Scientific name: Quartz (SiO₂) with likely calcite (CaCO₃) and iron sulfides, possibly pyrite (FeS₂); exact species requires testing
Category: mineral
Identified: August 23, 2026
Method: Standard

AI Estimated Value

About $15–$100 for a common hand specimen; attractive, locality-documented pieces may bring $100–$300.

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

Likely a hydrothermal vein specimen formed when hot, mineral-rich fluids deposited quartz, carbonate, and sulfides in fractures; age depends on its mining district and cannot be determined visually.

Uses & applications

Primarily a collector specimen; quartz and calcite are industrial minerals, while pyrite may be an ore indicator but this piece is not economically useful for extraction.

Geological facts

The red-orange coloration commonly reflects hematite or limonite weathering of iron-bearing minerals. Acid testing, streak, hardness, and crystal examination would distinguish calcite and pyrite from similar minerals.

Field identification & locations

Look for six-sided quartz crystals, rhombohedral calcite, and brassy cubic or granular sulfides. Common settings include hydrothermal veins and metal-mining districts worldwide.