Snooping Around

Pennsylvania musical rocks Looking at the boulders that dot the Ringing Rocks County Park (PA) , it seems to see a show already seen hundreds of times throughout the world . But those stones are every thing but common. In fact , a simple beat against them   produces a metallic sound . If you wouldn't know we're talking about rocks , you'll probably say the sound produced is due to some metallic objects. But this is not the case! The nature of this strange phenomenon has perplexed scientists for years, and even today there are various assumptions, but it is not known yet why these rocks produce this unusual sound. It seems , from studies , that these rocks are made of a substance called diabase which is basically volcanic basalt.They also have a high content of iron and aluminum, which explain the metallic behaviour. But the weird thing is the sound. In fact is  not the single rock to resonate , but all t...