mineral
Quartz geode/vug specimen
Quartz (SiO₂), likely in a weathered iron-oxide-rich host rock
AI-generated identification · may be incorrectWhite to translucent drusy quartz crystals line an open cavity; crystals have vitreous luster, irregular fracture, and Mohs hardness 7. The tan-orange coating is likely limonite/goethite, with no obvious cleavage.
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Physical properties
White to translucent drusy quartz crystals line an open cavity; crystals have vitreous luster, irregular fracture, and Mohs hardness 7. The tan-orange coating is likely limonite/goethite, with no obvious cleavage.
Formation & geological history
Formed when silica-rich groundwater deposited quartz crystals inside a gas cavity, fracture, or dissolution void in volcanic or sedimentary rock; the exact age and host rock cannot be determined from the image.
Uses & applications
Used as a decorative and collecting specimen; quartz is also important in glassmaking, electronics, abrasives, and engineered stone. This small hand specimen has modest aesthetic value.
Geological facts
The sparkling interior is a druse—a coating of many tiny intergrown crystals—rather than a single large crystal. Iron oxides commonly stain quartz yellow, orange, or brown.
Field identification & locations
Identify by its glassy sparkle, hardness, lack of cleavage, and inability to scratch it with a steel knife; a vinegar test is generally uninformative. Quartz-lined cavities occur worldwide, especially in volcanic regions and hydrothermal veins.
