Photo of the Ringing Rocks near Pipestone, Montana
Photo of the Ringing Rocks near Pipestone, Montana

Weekly Gem #238, Now that’s what I call “hard rock music!”

Published 8/8/20

Location: This hidden gem is located about 5 miles north of Pipestone, MT (see the Clue Me! Map). To get there, you’ll need a high clearance 4WD … or a rusty, 2007 Mazda 3 (zoom zoom).

These boulders ring like a bell when you tap them with a hammer! Each place you tap has its own pitch, so with enough people and hammers you could play the rocks like a bell choir.

The pile of boulders is a remnant of the central core from a 76 million year old volcano. You might think that ‘magma is magma,’ but at least in this small section of the volcano, there were discrete olivine, basalt, and granite magmas. These swirled and mixed as they cooled, but imagine something of a taffy consistency, where the magmas twisted together with partial and uneven mixing. Not like a milkshake where everything is blended.

The result was thousands of hard rocks, wrapped in miles of easy-listening (i.e softer) rock. Millions of years later, the soft rock has disappeared, leaving behind this pile of musical boulders.

There are sonorous rocks (ringing rocks) in a few other places in the world - India, Namibia, England, and Mexico.

It is not yet understood why these rocks ring! That's right - we can send people to the moon, but we can't figure out what makes some rocks ring and others clunk. 


Here's the hidden gem entry from our Clue Me! map.


Ding, Dong, Ring-a-ling-a Ding Dong


The Ringing Rocks

Why It's Interesting

These unique rocks ring when you tap them with a hammer. Scientists still don't understand what makes these rocks ring.

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