The Resurgence of Ojuela: From Ghost Town to Gemstone Haven
0:00:00 Ojuela's History: Ojuela, a ghost town in Durango, Mexico, was once a thriving silver mining town from 1598 for about 350 years.
0:00:17 The Puente de Ojuela: A 300-meter long suspension bridge, built by the same people who constructed the Brooklyn Bridge, stands as a testament to the town's past prosperity. It was once the world's third-longest suspension bridge.
0:00:29 A Geological Renaissance: The town is experiencing a revival due to the discovery of valuable secondary minerals in its abandoned mines.
0:01:09 The Silver Route: Ojuela was a key location on the UNESCO-recognized "Silver Route," used for trading silver between Mexico and the United States.
0:01:25 Formation of Ore Deposits: The gold and silver deposits were formed by hydrothermal fluids from magma that pushed through Cretaceous-age limestone.
0:01:55 Mining Yields: The mines produced significant quantities of silver (2.5 million kg), gold (17,000 kg), and lead (816,466 metric tons).
0:02:19 The Discovery of Secondary Minerals: Weathering of the original ore deposits led to the formation of secondary minerals, which are created when preexisting rocks are altered at the Earth's surface by exposure to water and oxygen.
0:02:57 Useful Secondary Minerals: Some secondary minerals, like kaolinite (used in pottery) and gibbsite (used for aluminum extraction), have practical applications.
0:04:23 Adamite Discovery: In 1946, collectors found beautiful lime-green, bubble-shaped adamite crystals, a zinc arsenate hydroxide, in the Ojuela mine.
0:05:11 Adamite Colors: Adamite crystals can vary in color depending on their composition: clear or white when pure, yellow with iron, lime-green with copper, pink with cobalt, and purple with manganese.
0:05:54 Treasure Trove of Gems: Subsequent exploration revealed over 100 different brightly colored secondary minerals in the mine.
0:06:15 A Second Life: Miners found that these colorful gems were more valuable than the remaining gold and silver, leading to a resurgence for Ojuela.
0:06:25 SciShow Rocks Box: Subscribers to the SciShow Rocks Box can receive a piece of adamite on limonite from the Ojuela mine.