Geodes are rocks that contain a hollow space inside of them. This space is often lined with crystals. Most geodes are small, but a few huge ones have been found. Two candidates are said to have the world’s largest geode. One is in Spain, and the other is in Ohio. Some fantastic amethyst geodes have been found in Uruguay.
The Pulpi Geode In Spain
This massive 390 cubic foot (11 cubic meters) geode is located in an abandoned silver mine near Pulpí, Spain. It is the largest in the world and is lined with massive selenite crystals up to 6 feet long. These selenite crystals are incredibly pure and translucent so you can see your hand through them.
This geode was formed in two different phases. The first happened around 6 million years ago. An ample, hollow space formed in the rock as acidic water dissolved the soluble dolomites, which include the Sierra del Aguilón mountain range. Then, as the water temperature and chemistry changed, gypsum settled out of the groundwater, forming selenite crystals along the walls of the cavity. Based on how big the gypsum crystals are, scientists think they began to grow less than 2 million years ago.
In 1999, a group of mineralogists entered an old mine and found the Pulpi Geode. For years it was sealed off to prevent vandalism, but in August 2019, it was opened to the public for tours.
Some people say that the Pulpi geode might not count as a classic geode because it is not perfectly spherical.
The Crystal Cave In Ohio
There is a massive celestite crystal-lined geode located near Put-in-Bay, Ohio. This geode is said to be the largest one ever found. It is 30 feet (10 meters) long, but it was larger when it was first discovered.
In 1887, Gustav Heineman found a geode while digging a well beneath his winery. The walls of the geode were lined with tabular celestite crystals up to 3 feet long. Gustav mined the celestite crystals for their strontium, which fireworks use to create a red flame. However, he decided to halt mining and turn the crystal cave into a tourist attraction. Visitors can tour the natural phenomenon today at the Heineman Winery.
People have made different claims about the size of this geode. But because of conflicting and incomplete dimensions, it isn’t easy to verify the size of this geode.
Massive Amethyst Geodes From Uruguay
The 120 million-year-old basalt flows in Artigas, Uruguay, are famous for their dark purple amethyst geodes. The geodes started as gas bubbles trapped in molten lava when it cooled. Over time, groundwater precipitated silica inside these cavities, forming quartz crystals on the walls. Most of these geodes are smaller than a foot in diameter, but some can be very large.
Some amethyst geodes from Uruguay are nice. They’re not as big as the Pulpi Geode or Ohio’s crystal cave, but they’re still pretty impressive.
The largest amethyst geode is at China’s Shandong Tianyu Museum Of Natural History. It’s 9 feet 10 inches (3 meters) long, 5 feet 10 inches (1.8 meters) wide, and 7 feet 2 inches (2.2 meters) high. But there are amethyst geodes that are bigger.
This Uruguayan amethyst geode is located at the Crystal Castle & Shambhala Gardens in Byron Bay, Australia. It weighs over 44,000 lbs (20,000 kg) and is an astounding 18 feet (5.5m) wide. A farmer reportedly found it in Artigas, Uruguay.
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Frequently Asked Questions About World’s Largest Geode
The most expensive geode is The Empress of Uruguay. This amethyst-bearing geode is 3.27 tall and 2.5 tons in weight. It was initially purchased for $75,000 in 2007 but is now estimated to be worth around $200,000.
The Empress of Uruguay, a gigantic Amethyst geode initially discovered in the Artigas region in northern Uruguay, now stands in the Crystal Caves in Atherton, Australia. This massive specimen is 3.27 meters tall and weighs 2.5 tonnes!
Geodes can be worth a lot of money. The price for a geode can be anywhere from $5 to more than $1000. It depends on the type of geode and where it is from. Geodes that have crystals inside them are more valuable than ones that don’t.
Although the geode is embedded in ancient rocks, the crystals are much younger. Radiometric dating of some of the oldest ones shows that they formed less than 5.6 million years ago. But probably not more than 2 million years ago, says a new study in Geology published this week.