Nobody knows for sure exactly why the rocks ring like bells when
struck with a hammer is a mystery. The rocks do contain a
significant amount of iron, which might be part of the
explanation. However, the high iron content doesn’t explain two
other strange qualities that the rocks possess . . . Not all of
the rocks ring when struck, and they don’t ring when they are
removed from the site, suggesting that the ringing has something
to do with the way the rocks lay against one another. Larger
flat ones seem to produce an especially impressive sound when
struck. Compared to the neighbors . The Ringing Rocks are very
small part (160 acres) of a mountainous region called the
Boulder Batholith, which encompasses a large portion of
southwestern Montana. Batholiths originate when magma cools
slowly beneath the surface to form granite. Edited by zoser, 04
February 2013 - 07:53 PM.