sedimentary

Hag Stone (Adder Stone / Geode-bearing Pebble)

Sedimentary Rock with Cavity (often Quartzite, Limestone, or Sandstone)

AI-generated identification · may be incorrect

Hardness: 5.5-7 on Mohs scale depending on matrix, Color: Light grey to beige with a dark interior void, Luster: Dull to earthy exterior, crystalline inside cavity, Texture: Smooth, water-worn pebble surface with a naturally weathered or geode cavity hole.

Hardness: 5

Identified July 24, 2026More sedimentary →

Explore Hag Stone (Adder Stone / Geode-bearing Pebble) in the encyclopedia →

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Physical properties

Formation & geological history

Formed through fluvial or coastal wave action tumbling a sedimentary matrix rock containing a softer mineral inclusion, fossil shell, or small vug cavity that weathered away faster than the surrounding rock, leaving a hole.

Uses & applications

Traditionally used as folk amulets, protective charms, decorative garden pebbles, jewelry pendants, or pocket stones for collectors.

Geological facts

Hag stones (also called adder stones, witch stones, or holey stones) are naturally perforated pebbles. European folklore holds that looking through the hole allows one to see fairies, spirits, or dispel curses.

Field identification & locations

Identify in the field by checking that the hole passes through or deep into the pebble naturally rather than being drilled mechanically. Commonly found on gravel beaches, riverbeds, and glacial wash deposits.