mineral

Quartz-rich hydrothermal specimen, likely milky quartz with calcite

Quartz (SiO₂), with probable calcite (CaCO₃) and iron-oxide staining

AI-generated identification · may be incorrect

White to translucent, vitreous-to-pearly luster, irregular masses with drusy and bladed crystals; quartz hardness 7, calcite 3, and specific gravities about 2.65 and 2.71. The apparent layered, cleavage-like crystals may be calcite, though image-only identification is uncertain.

Identified August 22, 2026More mineral →

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At a glance

Common name: Quartz-rich hydrothermal specimen, likely milky quartz with calcite
Scientific name: Quartz (SiO₂), with probable calcite (CaCO₃) and iron-oxide staining
Category: mineral
Identified: August 22, 2026
Method: Standard

AI Estimated Value

Approximately $10–$75 for a common rough specimen; $100+ if crystals are unusually large, attractive, or locality-labeled.

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 formed in a hydrothermal vein or cavity when mineral-rich fluids deposited quartz and carbonate crystals in fractures, commonly during Mesozoic–Cenozoic hydrothermal activity. Exact age and locality require geological context or testing.

Uses & applications

Quartz specimens are collected and used for silica, glass, abrasives, and electronics; calcite is used in cement, aggregate, fillers, and acid neutralization. This rough piece has modest decorative and educational value.

Geological facts

Quartz lacks cleavage and scratches glass; calcite has three good cleavage directions and effervesces strongly with dilute hydrochloric acid. Iron oxides produce the tan-brown staining.

Field identification & locations

Common in mineralized veins, geodes, limestones, and volcanic-hosted cavities worldwide. Test suspected calcite with acid, check hardness, and use a loupe or X-ray diffraction for confirmation.