Agate (Carnelian-Blue Agate mix)

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Translucent gray-blue with orange-red patches; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microcrystalline/cryptocrystalline quartz); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.64

Formation & Geological History

Formed in volcanic cavities or sedimentary pockets where silica-rich groundwater deposits layers over thousands of years. This tumbled specimen likely shows a mix of blue chalcedony and carnelian-style iron inclusions.

Uses & Applications

Commonly used in jewelry, decorative ornaments, lapidary arts, and as a pocket stone for collectors due to its aesthetic appeal and durability.

Geological Facts

Agate was named by the Greek philosopher Theophrastus, who discovered the stone along the shore line of the Achates River in Sicily. It is a variety of chalcedony.

Field Identification & Locations

Identify in the field by its translucency, waxy surface when broken, and banding patterns (though bands may be faint in tumbled pieces). Found worldwide in volcanic rock regions like Brazil, India, and the United States (Lake Superior/Oregon).

Identified on: 4/13/2026

Mode: Standard