The Ringing Rocks
In a field of boulders in Pennsylvania, some rocks ring like bells when you strike them with a hammer.
What was reported
In a forest in Bucks County, a field of bare boulders stretches across several acres, with no trees growing on it. Strike some of the rocks with a hammer, and they ring like metal bells; others nearby just thud.
In 1890, a local doctor gathered rocks of different pitches and played them with a band. Visitors still bring hammers to play them today.
Explanations offered
The rocks are diabase, a dense volcanic rock. Geologists think the ringing ones hold internal stress from repeated freezing and thawing, which lets them vibrate. Why some ring and others don't, and why nothing grows in the field, is not fully understood.
- When
- Known since the 1800s
- Where
- Ringing Rocks Park, Upper Black Eddy, Pennsylvania, USA
- Witnesses
- Visitors every day
- Status
- Partly explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.