sedimentary
Hag Stone (Flint with natural hole)
Silicon Dioxide (SiO2) - Nodular Chert / Flint
Hardness of 7 on the Mohs scale, waxy to dull luster, conchoidal fracture, grayish-blue to brown color with a chalky outer cortex and a naturally eroded hole through the center.
Identified More sedimentary →
Explore Hag Stone (Flint with natural hole) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness of 7 on the Mohs scale, waxy to dull luster, conchoidal fracture, grayish-blue to brown color with a chalky outer cortex and a naturally eroded hole through the center.
Formation & geological history
Formed in Cretaceous chalk deposits from the accumulation of microscopic silica-rich sponge spicules and radiolarians. The hole is created through long-term water erosion, wave action, or the decay of an ancient organism trapped in the nodule.
Uses & applications
Historically used as protective amulets in folklore to ward off evil spirits and bad dreams. Also collected by rockhounds, used in natural crafts, and made into pendants.
Geological facts
Hag stones (also known as adder stones, witch stones, or holey stones) have a rich history in Celtic and European folklore. Legend holds that looking through the hole allows a person to see the fairy realm or reveal hidden truths.
Field identification & locations
Easily identified by a naturally occurring hole worn entirely through a hard flint or chert matrix. Commonly found along UK beaches, northern European coasts, and chalk beds.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale
Argillaceous sedimentary rock
sedimentary
Mudstone
Argillite / Siliciclastic sedimentary rock
sedimentary