mineral

Blue Chalcedony (Agate)

Cryptocrystalline Quartz (SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Pale blue to bluish-grey with waxy luster; Crystal Structure: Trigonal (microscopic); Cleavage: None; Specific Gravity: 2.6

Hardness: 6
Color: Pale blue to bluish-grey with waxy luster

Identified June 18, 2026More mineral →

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Physical properties

Hardness: 6.5-7 (Mohs scale); Color: Pale blue to bluish-grey with waxy luster; Crystal Structure: Trigonal (microscopic); Cleavage: None; Specific Gravity: 2.6

Formation & geological history

Formed via the deposition of silica from groundwater in cavities of volcanic rocks or sedimentary formations over millions of years, often in low-temperature hydrothermal environments.

Uses & applications

Primarily used as a gemstone in jewelry (cabochons, beads), decorative carvings, and as a collector's specimen. Known as a 'nurturing stone' in metaphysical circles.

Geological facts

The name 'chalcedony' comes from the ancient Greek town of Chalkedon. It is a fibrous variety of quartz where the crystals are too small to be seen without high magnification.

Field identification & locations

Identify by its waxy luster, conchoidal fracture, and lack of visible crystalline structure. Common in Turkey, Namibia, and the USA.

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Mineral/Rock

Banded Gneiss (River Rock/Pebble)

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Metamorphic Rock

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mineral