The Pulpí Geode, the largest in Europe and second in the world, has opened to visitors 20 years after being discovered in southern Spain.
The crystal cave is a major attraction in the Pilar de Jaravía area due to its size and the transparency of the rocks.
It is located 50 meters beneath Mina Rica, a silver mine that closed in the 1960s.
”Everybody comes to visit the geode, but once they’re here, they find a spectacular mine," Mila Carretero, geologist and visit coordinator at Mina Rica, told Efe.
"The mine has an incredibly large variety of minerals.
"One of them is a needle-shaped celestine covered with plaster crystals."
Pulpí is the biggest accessible crystal geode in the world.
The world’s largest, with crystals 10 feet long, is located in the Mexican state of Chihuahua.
However, its difficult location, a temperature of almost 50C and 100% humidity make it impossible for visitors to access.
Visitors to the cave in Spain have to walk down a mineshaft before descending a staircase that leads to the vast caverns of the mine and arrive at the geode, an opening in the rock covered with white crystals that measure two meters in length.
“We could read a book through these crystals,” Carretero said.
The rock at Mina Rica is dolomite, a type of limestone, which in the past was fractured and filled with a hot mineral-rich fluid.
Over the years, the dolomite dissolved and the fluid created an egg-shaped cavity.
The cooling of the liquid and the tectonic calm caused the formation of plaster crystals.
Pulpí's geode was discovered in 1999 by members of the Mineralogist Group of Madrid, who found a fracture with “impressive plaster crystals”.
"They went to take them and when some were ripped off they found a little hole, so they continued digging until they found the geode," Carretero added.
Work to make the cave accessible started eight years ago.
“The project was difficult because it needed credibility,” Juan Bautista López, councilor for tourism and deputy mayor of Pulpí, said.
“We started in 2011 when finding funding was difficult due to the crisis.”
The City Council, professor José María Calaforra from the University of Almería and the Spanish National Research Council supported the project.
In 2015 a virtual reality reconstruction of the site allowed experts “to see the characteristics of the mine and the vastness of the geode,” Bautista said.
The works started in May 2018 and were planned in two phases.
The first step consisted of preparing the main gallery, while during the second phase a staircase was installed so that the geode could be visited.
“Along the way, we have found another series of geodes and very interesting things from a geological-mining point of view," Bautista said.
"There are kilometers to discover and that is the goal for the next few years." EFE-EPA.