gemstone

Polished dendritic agate (likely moss or plume agate)

Microcrystalline quartz, chiefly chalcedony (SiO₂), with iron-oxide inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; translucent milky gray to pink chalcedony with cream, rusty, and moss-like inclusions, waxy-to-vitreous luster, cryptocrystalline structure, and no visible cleavage. The rounded edges indicate cutting and polishing.

Identified September 20, 2026More gemstone →

Explore Polished dendritic agate (likely moss or plume agate) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

At a glance

Common name: Polished dendritic agate (likely moss or plume agate)
Scientific name: Microcrystalline quartz, chiefly chalcedony (SiO₂), with iron-oxide inclusions
Category: gemstone
Identified: September 20, 2026
Method: Standard

AI Estimated Value

Approximately $5–$30 for a small polished piece; $30–$100+ for unusually attractive patterning, size, or documented provenance.

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

Forms when silica-rich groundwater fills cavities and fractures in volcanic rocks, depositing chalcedony in layers; iron and other minerals create the dendritic or plume patterns. Individual agate formation ages vary, commonly Paleozoic to Cenozoic.

Uses & applications

Used for cabochons, beads, carvings, ornamental objects, and decorative slabs; generally valued as an attractive lapidary material rather than for industrial use.

Geological facts

Agate patterns are often unique, and dendritic markings are mineral inclusions rather than fossils or plant material. Pink coloration may reflect iron staining or subtle treatment.

Field identification & locations

Identify by its translucency, very fine quartz texture, conchoidal fracture, and hardness sufficient to scratch glass; common sources include Brazil, Uruguay, Mexico, India, and the western United States.