mineral
Chalcedony Geode Fragment (Botryoidal)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
AI-generated identification · may be incorrectHardness: 6.5-7 Mohs scale; Color: Milky white to greyish-blue; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microscopic); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.64.
- Hardness
- 6
- Color
- Milky white to greyish-blue
- Luster
- Waxy to vitreous
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Physical properties
Hardness: 6.5-7 Mohs scale; Color: Milky white to greyish-blue; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microscopic); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.64.
Formation & geological history
Formed through the deposition of silica-rich groundwater in the volcanic cavities or sedimentary pockets. These often grow in layers over thousands of years, typically in Tertiary or Cretaceous formations.
Uses & applications
Primarily used for geological collecting, educational displays, and sometimes tumbled for lapidary use or jewelry making.
Geological facts
The bubbly, grape-like appearance is called 'botryoidal' texture. This specimen specifically shows 'agate' layering within a small vug or geode pocket.
Field identification & locations
Identify by its waxy luster, hardness (it will scratch glass), and the rounded botryoidal internal surface. Common in volcanic regions with high mineral turnover.
