mineral

Blue Chalcedony

Silicon Dioxide (SiO2)

Hardness: 6.5–7; Color: Translucent grayish-blue to light lavender; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58–2.64

Hardness: 6
Color: Translucent grayish-blue to light lavender
Luster: Waxy to vitreous

Identified June 19, 2026More mineral →

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Physical properties

Hardness: 6.5–7; Color: Translucent grayish-blue to light lavender; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58–2.64

Formation & geological history

Formed through the deposition of silica-rich water in volcanic cavities or sedimentary layers at relatively low temperatures. It often occurs as a primary precipitate in late-stage hydrothermal environments.

Uses & applications

Predominantly used as a gemstone for jewelry (cabochons and beads), ornamental carvings, and by mineral collectors for its soothing aesthetic.

Geological facts

Chalcedony is a cryptocrystalline form of silica, meaning its crystals are so small they can only be seen under extreme magnification. Blue chalcedony is often linked to calming folklore and the 'throat chakra' in metaphysical circles.

Field identification & locations

Identify by its waxy luster, lack of visible crystals, and conchoidal (shell-like) fracture. Commonly found in Brazil, Turkey, Namibia, and the USA. Collectors should look for even color saturation and high translucency.