mineral

Blue Chalcedony

Cryptocrystalline Quartz (SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Pale blue to lavender-blue; Luster: Vitreous to waxy; Crystal structure: Trigonal/monoclinic; Cleavage: None; Specific gravity: 2.58-2.64

Hardness: 6
Color: Pale blue to lavender-blue
Luster: Vitreous to waxy

Identified May 22, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Pale blue to lavender-blue; Luster: Vitreous to waxy; Crystal structure: Trigonal/monoclinic; Cleavage: None; Specific gravity: 2.58-2.64

Formation & geological history

Formed through the deposition of silica from aqueous solutions at relatively low temperatures in cavities of volcanic and sedimentary rocks. Common in hydrothermal veins.

Uses & applications

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

Geological facts

The name 'Chalcedony' is believed to come from the ancient Greek town of Chalkedon in Asia Minor. It is often referred to as 'Blue Lace Agate' when it possesses banded patterns.

Field identification & locations

Identify by its characteristic waxy luster, translucency, and conchoidal fracture. Often found in pockets of basalts or as nodules in desert regions like Namibia and Turkey.