sedimentary
Agate in Host Rock
Silicon dioxide (Chalcedony/Quartz) within limestone or volcanic matrix
AI-generated identification · may be incorrectHardness of 6.5 to 7 on the Mohs scale, waxy luster, conchoidal fracture, and varicolored banding within a dull brown matrix.
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Physical properties
Hardness of 6.5 to 7 on the Mohs scale, waxy luster, conchoidal fracture, and varicolored banding within a dull brown matrix.
Formation & geological history
Formed via silica-rich groundwater solutions depositing microcrystalline quartz inside cavities of host rock over millions of years.
Uses & applications
Used primarily in lapidary arts, ornamental carving, and mineral specimen collecting.
Geological facts
Agate nodules often form in gas cavities within volcanic rocks or within limestone cavities as replacement fossils.
Field identification & locations
Identify by testing matrix hardness and observing distinct chalcedony layering in cavity fillings; found globally in volcanic and sedimentary regions.
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