Description
A cryptocrystalline variety of silica, showing a variegated banded structure and waxy luster. Agate bands are due to the deposition of successive mineral layers from solution and may be either straight, wavy, or concentric. Agate is slightly harder than quartz. It has been gathered or mined since Neolithic times. Sources for agate include western Asia, India, Brazil, Uruguay, and Germany. Onyx is a type of agate in which the bands are parallel. Sardonyx is a variety of onyx that has alternating red and cream layers. Moss agates contain brown dendritic or fernlike patterns. Agates are used for gemstones, beads, amulets, mortars and pestles, burnishers for gilding, textile rollers, knife edges, and as ornamental stones.
Synonyms and Related Terms
Achat (Deut.); agat (Dan., Pol.); ágata (Esp., Port.); agathe (Fr.); agaat (Ned.)
Examples include: onyx; sardonyx
Other Properties
Fracture = conchoidal. Luster = vitreous to waxy. Streak = white to none
Colors may include white, grey, light blue, orange, red, and black.
Crystal system=hexagonal
Hazards and Safety
May contain silica dust; chronic inhalation can cause silicosis.
Additional Information
Mineralogy Database: Quartz
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Last updated on: 3/9/2010 9:44:51 AM
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