Researchers discovered a rare high-pressure mineral called reidite at the Rock Elm impact site. It is for this reason the rock elm is sometimes called the cork elm. She had an all-wood hull, described as "double diagonal Honduras mahogany on Canadian rock elm". The disturbance is named for Rock Elm, Wisconsin, a nearby community. The largest Rock Elm in the United States is located near the library. Rock elm is also unusual among North American elms in that it is often monopodial.