Rare Volcanic Breccia from the Radersburg Mining District, Montana (1860s) This rare specimen of volcanic breccia hails from the historic Radersburg Gold Mining District in Montana, a site renowned during the 1860s Gold Rush. This breccia features an intricate mosaic of angular volcanic fragments cemented within a fine-grained matrix, each fragment a testament to the intense volcanic activity that shaped the region millions of years ago. The breccia's varied clasts include rhyolite, andesite, and basalt, reflecting the diverse volcanic processes at play. What makes this sample particularly rare is its association with gold-bearing hydrothermal veins. During the 19th-century mining boom, prospectors sought not just gold nuggets but also auriferous (gold-containing) breccias, which sometimes hosted fine disseminated gold or were indicators of nearby quartz veins rich in ore. This historical significance, combined with the breccia's diverse mineralogy and geological story, captures the spirit of a transformative era in Montana's mining history. Collectors and geologists value such specimens not only for their aesthetic appeal but also for their connection to the pioneering days of Western gold exploration.