A post shared on Facebook over 170 times purportedly shows images of fulgurites that resulted from lightning striking sand.

Facebook/Screenshot

Verdict: False

The photos actually show sandcastles made by an artist.

Fact Check:

When it strikes quartz sand or rock, lightning can produce glass tube or crust formations called fulgurites, phenomena observed on beaches, in deserts and on mountains, according to the Utah Geological Survey. Fulgurites have been discovered around the globe, the Oxford University Museum of Natural History states on its website.

In the two pictures in the Facebook post, sand formations can be seen jutting out of the ground on beaches. The caption identifies the unusual shapes as fulgurites caused “when lightning strikes sand.” (RELATED: Viral Image Claims To Show Raleigh, North Carolina Beach)

In reality, the formations in both of the pictures are actually sandcastles created by an artist. The top photo can be found in an August 2015 article published by The Atlantic about then-Harvard University sociology lecturer and sandcastle artist Matt Kaliner. That photo and others included in the story depict various sandcastles Kaliner has built, per The Atlantic.

Kaliner posted the top and bottom photos on Flickr in 2007, both of which he explained were sandcastles he had built. The sandcastles are created using driftwood, dripped sand and, at times, string, according to WBUR. Pictures of other sandcastles he made can also be found on Flickr.

Some fulgurites are roughly the size of a coin, as seen in an image displayed on the Utah Geological Survey website. However, their size can vary significantly. A University of Florida group unearthed a fulgurite in 1996 measuring an unprecedented 16 feet in length, according to Guinness World Records.