sedimentary

Hag Stone (Sandstone with Boreholes)

Bored Sandstone (Sedimentary rock with lithophaga-style borings)

AI-generated identification · may be incorrect

Hardness: 6-7 (quartz-based); Color: Tan, beige, reddish-brown; Luster: Dull/Earthy; Crystal Structure: Clastic; Features smooth, rounded holes created by biological or mechanical erosion.

Hardness: 6-7 (quartz-based)
Color: Tan, beige, reddish-brown
Luster: Dull/Earthy

Identified May 31, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (quartz-based); Color: Tan, beige, reddish-brown; Luster: Dull/Earthy; Crystal Structure: Clastic; Features smooth, rounded holes created by biological or mechanical erosion.

Formation & geological history

Formed through the accumulation of sand-sized mineral particles over millions of years (clastic sedimentation). The holes are often created by marine mollusks (piddocks) or turbulent water action in coastal or river environments.

Uses & applications

Primarily used as a curiosity, pocket charm, or garden ornament. In history, used as protective amulets in folklore.

Geological facts

Also called 'Odin stones' or 'adder stones', these have been used for centuries in folklore for protection against bad luck or to 'see' into the spiritual realm through the hole.

Field identification & locations

Identify by looking for natural, through-and-through holes in water-worn sedimentary rocks. Commonly found on beaches or in riverbeds where water energy or boring organisms are present.