sedimentary

Hag Stone

Perforated Flint / Chert Node

Hardness: 6.5-7 on Mohs scale; Color: Tan, beige, brown, and yellowish exterior with a dark inner core; Luster: Dull to waxy; Structure: Microcrystalline quartz; Specific Gravity: ~2.65.

Hardness: 6
Luster: Dull to waxy

Identified July 24, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Tan, beige, brown, and yellowish exterior with a dark inner core; Luster: Dull to waxy; Structure: Microcrystalline quartz; Specific Gravity: ~2.65.

Formation & geological history

Formed in sedimentary rocks like chalk or limestone where silica rich fluids deposited microcrystalline quartz around organic matter or through wave erosion, ice action, and groundwater dissolution creating a natural hole.

Uses & applications

Used historically as protective amulets, folklore charms, decorative specimens, and jewelry components.

Geological facts

Also known as adder stones, witch stones, or holey stones. According to European folklore, looking through the hole allows one to see the unseen world, fairies, or witches, and they were hung over doorways or bedposts to ward off evil.

Field identification & locations

Identified by a naturally occurring hole worn all the way through a hard pebble or stone (usually flint, chert, or limestone). Frequently found along ocean beaches, riverbeds, and chalk deposit regions.