sedimentary
Hag Stone (Chert/Flint with natural perforation)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Hardness: 6.5-7 Mohs; Color: Brown, tan, ochre; Luster: Dull to waxy; Texture: Fine-grained, crypto-crystalline; Features: Natural weathering hole created by boring organisms or water erosion.
- Hardness
- 6
- Color
- Brown, tan, ochre
- Luster
- Dull to waxy
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Physical properties
Hardness: 6.5-7 Mohs; Color: Brown, tan, ochre; Luster: Dull to waxy; Texture: Fine-grained, crypto-crystalline; Features: Natural weathering hole created by boring organisms or water erosion.
Formation & geological history
Formed from silica-rich sediment in ancient marine environments, often during the Cretaceous or Jurassic periods. The hole is typically caused by water erosion or the boring of marine mollusks like piddocks over thousands of years.
Uses & applications
Primarily used as a lucky charm or talisman in folklore. Also used for decorative jewelry (pendants) or landscape accenting.
Geological facts
Hag stones are also known as Adder Stones, Holey Stones, or Witch Stones. In European folklore, looking through the hole was believed to reveal the spirit world or protect against the 'evil eye'.
Field identification & locations
Commonly found on rocky beaches or in riverbeds where water action is high. Identified by a naturally worn, smooth-edged hole passing completely through a hard, waxy rock specimen.
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