Blue Chalcedony

Physical Properties

Hardness: 6.5–7 on Mohs scale. Color: Pale blue, lavender-blue, or grey-blue. Luster: Vitreous to waxy. Crystal structure: Trigonal (cryptocrystalline). Cleavage: None. Specific gravity: 2.58–2.64.

Formation & Geological History

Formed from watery, silica-rich solutions at low temperatures, typically in volcanic cavities (vugs) or within sedimentary environments. They accumulate in layers through the slow precipitation of microscopic quartz crystals.

Uses & Applications

Commonly used in jewelry as cabochons, carvings, beads, and as decorative ornamental stones. High-quality specimens are popular for metaphysical collecting.

Geological Facts

Chalcedony is a cryptocrystalline variety of quartz, meaning its crystals are too small to be seen with a standard microscope. Blue Chalcedony is often called 'The Speaker's Stone' in holistic circles.

Field Identification & Locations

Identified by its waxy luster and blue-to-grey translucency. It is commonly found in Turkey, Namibia, India, and the United States (Oregon/California). In the field, look for botryoidal (grape-like) habits or smooth nodules.

Identified on: 4/24/2026

Mode: Standard