Petoskey Stones, the state stone of Michigan, are fossilized coral resulting from glaciation and are often polished to reveal the beautiful pattern of the 6 sided coral colonies. #Geology #Petoskey_Stone #Michigan
The Moeraki Boulders are a big attraction, found on Koekohe Beach near Moeraki on New Zealand’s coast. The huge, gray, spherical stones formed in sediment on the sea floor 60 million years ago and were revealed by shoreline erosion. The boulders, some of which stand alone and some in clusters, can weigh several tons and measure 10 feet across.
This is what sand looks like when it's been hit by lightning. Called a fulgurite, this is made up of natural hollow glass tubes formed in quartzose sand, silica, or soil by lightning strikes (at 3,270 °F), which instantaneously melts silica on a conductive surface and fuses grains together over a period of around one second. from I fucking love science