mineral
Likely tumbled quartz/chalcedony
Quartz (SiO₂), possibly milky quartz or pale chalcedony
AI-generated identification · may be incorrectHardness 7 (quartz) or about 6.5–7 (chalcedony); translucent cream-yellow body, vitreous to waxy luster, and no obvious cleavage. The rounded shape and surface suggest tumbling or natural abrasion.
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Physical properties
Hardness 7 (quartz) or about 6.5–7 (chalcedony); translucent cream-yellow body, vitreous to waxy luster, and no obvious cleavage. The rounded shape and surface suggest tumbling or natural abrasion.
Formation & geological history
Quartz crystallizes from silica-rich igneous and hydrothermal fluids; chalcedony forms as microcrystalline silica in cavities and fractures. Such material ranges from Precambrian to recent secondary deposits; age cannot be determined visually.
Uses & applications
Used for decorative stones, lapidary work, countertops, abrasives, and glass manufacture; attractive pieces may be used in inexpensive jewelry or collected.
Geological facts
Quartz is one of Earth’s most abundant minerals and has a Mohs hardness that allows it to scratch ordinary glass. The yellow tint may result from iron staining or surface coating.
Field identification & locations
Field tests include scratching glass, checking for a white streak, and observing translucent edges; it should not scratch steel readily. Common sources include quartz veins, river gravels, and weathered igneous rocks worldwide.
