sedimentary

Hagstone (Adder Stone)

Chert or Sedimentary pebble with natural perforation

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs); Color: Tan, brown, or buff; Luster: Dull to earthy; Composition: Primarily microcrystalline quartz (silica); Feature: Natural hole through the center.

Hardness: 6
Color: Tan, brown, or buff
Luster: Dull to earthy

Identified July 13, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Tan, brown, or buff; Luster: Dull to earthy; Composition: Primarily microcrystalline quartz (silica); Feature: Natural hole through the center.

Formation & geological history

Formed through the natural erosion of a sedimentary rock, where a softer part of the stone (like a fossil or softer mineral inclusion) is bored out by wave action, wind, or acidic water over thousands of years.

Uses & applications

Primarily collected as curiosities or used in folk magic and jewelry. Historically used as protective amulets.

Geological facts

Also called Witch Stones or Adder Stones, they were traditionally believed to allow the wearer to see through magical illusions or protect against the 'evil eye' and nightmares.

Field identification & locations

Identify in the field by looking for stones with naturally occurring, smooth-edged holes that penetrate all the way through. They are commonly found on beaches or in riverbeds where water erosion is high.