Hematite

This specimen features sharp, silvery-black metallic, platy hexagonal crystals of hematite to 2mm, on a matrix of white altered feldspar and rhyolite. The Thomas Range, located near Delta in western central Utah, is a north-south trending mountain chain composed of Miocene-aged rhyolite domes. The area experienced explosive, highly felsic volcanism, resulting in a diverse range of mineral species due to a complex mineralization history. Recognized as a valuable mining district since 1905, the range has attracted mineral collectors for over a century, though commercial mining attempts, particularly for uranium, were largely unsuccessful. The region’s rocks primarily consist of fine-grained, light-coloured, and often vuggy rhyolites and andesites, with quartz, sanidine, and biotite as the main minerals, along with occasional lenses of obsidian. Not to mention the wonderful topaz and bixbyite the locality is most known for!