gemstone

Blue-dyed agate (likely a polished agate cabochon)

Microcrystalline quartz, SiO₂ (chalcedony); likely artificially dyed blue

AI-generated identification · may be incorrect

Polished oval with translucent blue-and-white banding and a glossy luster. Quartz hardness is about 7 Mohs; trigonal crystal structure at the microscopic level, with no visible cleavage and conchoidal fracture. Specific gravity is typically about 2.6.

Identified October 15, 2026More gemstone →

Explore Blue-dyed agate (likely a polished agate cabochon) in the encyclopedia →

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Physical properties

Formation & geological history

Agate forms as silica-rich fluids fill cavities, commonly in volcanic rock, depositing concentric or irregular chalcedony bands. The visible vivid blue is likely added by dyeing; the original geological age cannot be determined from the image.

Uses & applications

Used for jewelry, cabochons, ornaments, and collecting. Agate is also used for small precision components and decorative objects.

Geological facts

Blue coloration this vivid is often produced by treating naturally pale agate; polished surfaces can make its banding especially prominent.

Field identification & locations

The layered, waxy-looking chalcedony pattern supports agate, though the image cannot confirm its identity or treatment. Agate occurs worldwide; at the reported location in northwestern Germany, a transported or traded specimen is more likely than a locally formed agate. Approximate value: $2–$20 as a small dyed cabochon.