mineral
Chalcedony (Agate / Quartz Beach Pebble)
Silicon Dioxide (SiO2)
Hardness 6.5-7 on the Mohs scale, translucent yellowish-orange hue, waxy to vitreous luster, conchoidal fracture, microcrystalline structure.
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Physical properties
Hardness 6.5-7 on the Mohs scale, translucent yellowish-orange hue, waxy to vitreous luster, conchoidal fracture, microcrystalline structure.
Formation & geological history
Formed by low-temperature deposition of silica from water solutions in cavities and fractures of host rocks, often weathered out and smooth-tumbled by wave action on beaches.
Uses & applications
Used in lapidary arts, jewelry making, ornamental carvings, and popular among beachcombers and rock collectors.
Geological facts
Agate and chalcedony pebbles found along ocean beaches are often termed 'beach agates' or 'water-dropped agates' due to their smooth, wave-polished appearance.
Field identification & locations
Identified by its translucency, resistance to scratching steel, lack of cleavage, and smooth rounded edges created by natural coastal erosion. Widely found along gravelly beaches worldwide.
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Potassium Feldspar (Orthoclase)
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