Flood basalt

Flood basalt was a type of basalt found on the planet Mustafar. In 14 BBY, the Imperial architect Colonel Alva Brenne came to Mustafar to design a personal base for the Dark Lord of the Sith Darth Vader. While surveying the planet's fiery terrain, she encountered flood basalt along Mustafar's lava flows, later instructing Lieutenant Roggo to run tests on the strength of the substance so that she might incorporate it into Vader's fortress.

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