mineral

Chalcedony/geode fragment (likely agate with druzy quartz)

Microcrystalline quartz, SiO₂, with possible iron-oxide staining and crystalline quartz

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; gray, brown, cream, and rust-orange coloration; waxy to vitreous luster with sparkling crystal surfaces. Quartz is trigonal and has no cleavage, breaking conchoidally; specific gravity is approximately 2.6.

Identified September 16, 2026More mineral →

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At a glance

Common name: Chalcedony/geode fragment (likely agate with druzy quartz)
Scientific name: Microcrystalline quartz, SiO₂, with possible iron-oxide staining and crystalline quartz
Category: mineral
Identified: September 16, 2026
Method: Standard

AI Estimated Value

About $5–$25 for a small ordinary specimen; $30–$100+ if strongly banded, crystal-lined, or attractively polished.

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 when silica-rich groundwater filled cavities in volcanic rock, depositing chalcedony and later quartz crystals; iron oxides produced the brown-orange colors. The specimen’s exact geological age cannot be determined from the image.

Uses & applications

Used as a decorative and lapidary stone, including cabochons, polished pieces, and specimen displays; ordinary fragments have modest commercial value.

Geological facts

Agate commonly develops concentric banding, while druzy quartz forms a sugar-like coating of tiny crystals. The image may also show weathered host rock or calcite, so exact identification requires hardness and acid tests.

Field identification & locations

Look for translucent chalcedony, curved banding, and quartz sparkle; quartz should scratch glass, while calcite fizzes in dilute hydrochloric acid. Common sources include Brazil, Uruguay, Mexico, India, and the western United States.