Rock Identifier
Tumbled Purple Agate (Silicon Dioxide (SiO2) - Chalcedony variety) — mineral
mineral

Tumbled Purple Agate

Silicon Dioxide (SiO2) - Chalcedony variety

Hardness: 6.5-7 on Mohs scale; Color: Purple (often dyed); Luster: Vitreous to waxy; Crystal Structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.58-2.64

Hardness
6
Color
Purple (often dyed)
Luster
Vitreous to waxy
Identified More mineral

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Purple (often dyed); Luster: Vitreous to waxy; Crystal Structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.58-2.64

Formation & geological history

Formed in cavities of volcanic rocks or ancient lavas, where silica-rich groundwater deposits layers of microcrystalline quartz over thousands of years. Natural purple agate is rare; most bright purple specimens are heat-treated and dyed.

Uses & applications

Used extensively in jewelry making, ornamental carvings, tumbled stones for therapy, and as decorative accents in home decor.

Geological facts

Agate is named after the Achates River in Sicily. It is one of the oldest healing stones and was famously used in Egyptian amulets and Babylonian cylinder seals.

Field identification & locations

Identify by its translucent nature, waxy luster when polished, and characteristic banding patterns if present. Often found in riverbeds or volcanic regions like Brazil and Uruguay.