mineral
Banded agate (likely)
Agate, a banded variety of microcrystalline quartz (SiO₂)
AI-generated identification · may be incorrectLikely Mohs hardness 6.5–7; dark brown to black with pale and pink bands, waxy to vitreous luster, and no visible cleavage. Agate is cryptocrystalline, with a trigonal quartz structure; the image alone cannot confirm the exact variety.
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Physical properties
Likely Mohs hardness 6.5–7; dark brown to black with pale and pink bands, waxy to vitreous luster, and no visible cleavage. Agate is cryptocrystalline, with a trigonal quartz structure; the image alone cannot confirm the exact variety.
Formation & geological history
Forms as silica-rich fluids deposit successive layers in cavities, commonly in volcanic rocks. The specimen’s age and geological setting cannot be determined from the image.
Uses & applications
Used for cabochons, beads, carvings, ornaments, and collectible polished stones.
Geological facts
Agate’s contrasting bands record changes in silica deposition and trace impurities.
Field identification & locations
Look for curved or concentric bands and a smooth, hard surface; common sources include Brazil, Uruguay, India, and the United States. This appears to be a polished slice or nodule, but identification is provisional from the image.
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