
sedimentary
Banded Agate
Cryptocrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness: 6.5-7 Mohs; Color: White and light blue-grey bands; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microscopic); Cleavage: None/Conchoidal fracture.
- Hardness
- 6
- Color
- White and light blue-grey bands
- Luster
- Waxy to vitreous
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Physical properties
Hardness: 6.5-7 Mohs; Color: White and light blue-grey bands; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microscopic); Cleavage: None/Conchoidal fracture.
Formation & geological history
Formed by the deposition of silica from groundwater in the cavities (vesicles) of igneous or sedimentary rocks. This specimen is likely from a secondary deposit found in riverbeds or volcanic regions, formed millions of years ago.
Uses & applications
Used extensively in jewelry making, lapidary arts, spiritual practices, and as decorative tumbled stones for collection.
Geological facts
Agate is named after the Achates River in Sicily. It is one of the oldest gemstones used in history, with Greek and Sumerian civilizations using it for seal stones and amulets.
Field identification & locations
Identified by its distinctive concentric or parallel bands and translucency. Common locations include Brazil, India, and the United States. In the field, look for smooth, waxy-surfaced nodules in gravel bars or volcanic outcrops.
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