mineral
Banded Agate (Polished Freeform/Nodule)
Silicon Dioxide (Microcrystalline Quartz, SiO2)
AI-generated identification · may be incorrectHardness 6.5–7 on the Mohs scale, waxy to vitreous luster, cryptocrystalline/trigonal structure, conchoidal fracture, specific gravity around 2.60–2.65. Displays translucent to opaque caramel-brown, tan, and soft white concentric banding.
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Physical properties
Hardness 6.5–7 on the Mohs scale, waxy to vitreous luster, cryptocrystalline/trigonal structure, conchoidal fracture, specific gravity around 2.60–2.65. Displays translucent to opaque caramel-brown, tan, and soft white concentric banding.
Formation & geological history
Formed as secondary silica deposits filling vesicles or cavities in volcanic rocks (such as basalts or rhyolites) or sedimentary rocks via silica-rich groundwater circulation over millions of years.
Uses & applications
Commonly used for lapidary work, cabochons, carvings, ornamental decor, decorative display specimens, and in metaphysical practices.
Geological facts
Agate has been used by humans for ornamental and tool-making purposes since the Neolithic era. Its name originates from the Achates River (now the Dirillo River) in Sicily, where it was first discovered by ancient Greeks.
Field identification & locations
Identified by its fine-grained quartz matrix, waxy feel, visible banding, and resistance to scratching by a steel blade. Found extensively in Brazil, Madagascar, Uruguay, and various volcanic regions worldwide.
