mineral

White Agate / Chalcedony

Silicon Dioxide (SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Translucent white to opaque milky white; Luster: Waxy to vitreous; Crystal structure: Trigonal (Microcrystalline); Cleavage: None/Conchoidal fracture; Specific gravity: 2.60-2.65

Hardness: 6
Color: Translucent white to opaque milky white
Luster: Waxy to vitreous

Identified March 25, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica from groundwater in the cavities of igneous (mostly volcanic) and sedimentary rocks. Common in basaltic occurrences. Geological age varies globally from Precambrian to Cenozoic.

Uses & applications

Commonly used in tumble stones, jewelry (cabochons, beads), decorative carvings, and historically used for mortar and pestles due to its high hardness and density.

Geological facts

Also known as the 'Stone of Hope,' white agate is often used in metaphysics for calming. Unlike crystalline quartz (like amethyst), its crystals are too small to be seen without high magnification, which gives it a smooth, waxy feel.

Field identification & locations

Identify by its waxy luster and inability to be scratched by a steel pocket knife. Found commonly in Brazil, India, and the United States (Lake Superior region and western states). For collectors: look for its distinctive translucency and lack of visible mineral grains.