These human-size crystals formed in especially strange ways New clues into ancient climate shifts reveal the possible origin story of Spain's Pulpí Geode, one of the world's largest.

The Pulpí geode was discovered in 1999 within an abandoned mine in southeast Spain. To trace its origins, the research team conducted a study of the geology and geochemistry of the mine, including a ...

Exactly when the geode of Pulpí formed is not known, but it was at some point after the Mediterranean Sea dried up 5.6 million years ago. Best estimates currently put the geode of Pulpí at ...

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Ultimately, the researchers narrowed down the geode's formation to a window of about 2 million years (not bad for the 4.5-billion-year-old calendar of geologic time).

The Pulpí Geode was formed in two different phases, starting six million years ago. At first percolating water dissolved the soluble limestone, creating a large cavity.

Amethyst geodes in Uruguay have been found in cooled lava flows, which date from the original breakup of the supercontinent Gondwana around 134 million years ago. However, their formation has ...

Mystery of Uruguay's amethyst geodes: New model to explain amethyst formation Date: October 2, 2024 Source: University of Göttingen Summary: Amethyst is a violet variety of quartz which has been ...

Researchers have revealed the geological processes behind the formation of amethyst and agate geodes in Northern Uruguay’s Los Catalanes District, offering new insights into mineral composition ...

Researchers studying amethyst geode formation in Brazil’s lava flows have proposed temperatures below 100 °C. The new study uses similar techniques and includes an additional oxygen isotope.