mineral

Yellow Chalcedony (Agate)

Silicon Dioxide (SiO2)

Hardness: 6.5-7 on Mohs scale. Color: Translucent yellow to honey-amber. Luster: Waxy to vitreous. Crystal structure: Cryptocrystalline (hexagonal/trigonal). Cleavage: None. Specific gravity: 2.58-2.64.

Hardness: 6
Color: Translucent yellow to honey-amber
Luster: Waxy to vitreous

Identified June 8, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica-rich fluids in cavities or veins within volcanic or sedimentary rocks. It often precipitates at low temperatures in igneous gas bubbles (vesicles).

Uses & applications

Predominantly used as a gemstone in jewelry (cabochons, beads), decorative carvings, and as a healing stone in folk traditions. Historically used for making tools and seals.

Geological facts

Yellow chalcedony is part of the quartz family. When it shows banding, it is technically an agate. It has been used by humans for thousands of years, specifically in the Mediterranean and Ancient Near East for signet rings.

Field identification & locations

Identify by its waxy luster, conchoidal fracture, and lack of visible crystals. It is commonly found in Brazil, India, Madagascar, and the USA. Collectors look for high translucency and uniform color.