sedimentary/metamorphic
Hag Stone (Holed Quartzite Pebble)
Quartzite (SiO2 based) with natural vug or erosion hole
Hardness: 7 (Mohs scale), Color: tan, grey, and buff with sandy textures, Luster: dull to earthy, Structure: microcrystalline quartz grains, Cleavage: none, Specific Gravity: approx 2.6
Identified More sedimentary/metamorphic →
Explore Hag Stone (Holed Quartzite Pebble) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale), Color: tan, grey, and buff with sandy textures, Luster: dull to earthy, Structure: microcrystalline quartz grains, Cleavage: none, Specific Gravity: approx 2.6
Formation & geological history
Formed initially from sandstone through metamorphism, and later tumbled in high-energy aquatic environments (rivers or shorelines). The hole is often created by boring organisms like piddock clams or by the preferential weathering of a softer mineral inclusion like calcite.
Uses & applications
Historically used as protective amulets in folklore to ward off evil spirits or 'the evil eye'. Today used for decorative garden stones, jewelry, and by mineral collectors interested in curious geological shapes.
Geological facts
In European folklore, looking through the hole of a hag stone was believed to reveal the 'invisible world' of fairies or spirits. They are also known as adder stones, witch stones, or holy stones.
Field identification & locations
Identify by looking for a naturally occurring hole that penetrates the entire stone or a deep natural cavity. Commonly found on beaches or in riverbeds where water erosion is constant.
More like this
Other sedimentary/metamorphic specimens
Tiger Iron
Tiger Iron (Hematite, Red Jasper, and Tiger's Eye)
metamorphic
Anthracite Coal
Anthracite (Carbon-based sedimentary-metamorphic rock)
metamorphic
Dalmatian Stone
Dalmatian Jasper (a misnomer) / Perthitic Igneous Rock
igneous
Anthracite Coal
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
metamorphic
Coal (Anthracite)
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
metamorphic
Blue Apatite
Apatite (Calcium Phosphate) - Ca5(PO4)3(F,Cl,OH)
mineral