December 26, 2016
The picturesque Bavarian town of Nördlingen, Germany, is situated in a crater filled with 72,000 tons of diamonds, according to a story posted Friday by Smithsonianmag.com.
Although the town's origins date back to 898 A.D., it wasn't until 50 years ago that scientists realized that the 9-mile-wide depression, known as the Ries crater, was formed by the impact of an asteroid. The intense pressure resulting from the asteroid crashing into the Earth caused the graphite-bearing rock in the region to transform into diamonds.
“We assume that the asteroid was a stony one with a weight of [approximately] three billion tons,” Gisela Pösges, a geologist and deputy director of the Ries Crater Museum in Nördlingen told Smithsonianmag.com. “[We think that] the asteroid was a similar size to the town of Nördlingen, about one kilometer (less than three-quarters of a mile) across.”
The diamonds formed from the asteroid impact will never find their way to the center of an engagement ring. The largest ones are 0.3mm in size (barely 1/100th of an inch). A 1mm diamond, by comparison, weighs 0.005 carats.
The high-pressure impact didn't only create diamonds, but also a material called suevite, which is a rock embedded with angular fragments of glass, crystal and diamonds.
Interestingly, when medieval residents set out to build the majestic St.-Georgs-Kirche church in the center of town, they used local materials to create the structure, including chunks of suevite. In fact, most of the town's structures were constructed with diamond-infused suevite.
“Our church, St. Georgs, is made of suevite [and contains] about 5,000 carats of diamonds,” Pösges told Smithsonianmag.com. “But they’re so tiny... that they have no economic value, only scientific value. You can observe the diamonds only with a microscope.”
Scientists estimate that the asteroid impact on Nördlingen generated 60 gigapascals of pressure. To turn carbon into diamonds, it takes between 24 and 136 gigapascal of pressure.
Guided tours of the diamond town of Nördlingen are regularly offered by the Ries Crater Museum, where suevite samples are on display.
Credits: Nördlingen photo via BigStockPhoto.com; Map by Googlemaps.com; Relief map by Batholith (Wikimedia Commons) [Public domain], via Wikimedia Commons. Suevite by H. Raab (User: Vesta) (Own work) [GFDL, CC-BY-SA-3.0 or CC BY-SA 2.0 at], via Wikimedia Commons.