mineral

Blue Lace Agate (Heat-treated/Crackle Quartz variety)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Sky blue with internal fractures, Luster: Vitreous, Crystal structure: Hexagonal/Trigonal (Cryptocrystalline), Cleavage: None, Specific Gravity: 2.60–2.65

Identified March 21, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: Sky blue with internal fractures, Luster: Vitreous, Crystal structure: Hexagonal/Trigonal (Cryptocrystalline), Cleavage: None, Specific Gravity: 2.60–2.65

Formation & geological history

Formed through the cooling of silica-rich groundwater in cavities of volcanic rock. The 'crackle' appearance in this specific specimen is often enhanced by quench-crackling (heating and then rapid cooling).

Uses & applications

Predominantly used for lapidary work, jewelry (beads, cabochons), meditation stones, and decorative home items.

Geological facts

While true Blue Lace Agate is naturally banded, many stones sold with this appearance are 'crackle quartz' dyed or heat-treated to achieve the intense blue and fractured texture seen here. Natural agate has been used by humans since the Neolithic era.

Field identification & locations

Identify by its waxy-to-glassy luster and internal spider-web fracturing. It is found globally, but famous agate deposits are in Namibia, Brazil, and the USA (Lake Superior). Collectors look for clarity and natural banding.

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