Uraninite (Crystal Cluster) — Cardiff Uranium Mine, Cardiff Township, Highlands East Township, Haliburton County, Ontario, Canada

Where individual uraninite crystals make a statement, a crystal cluster from a documented locality makes an argument: that the conditions of primary pegmatite crystallization produced not just isolated grains but a genuine mineral assemblage with textural integrity intact. Uraninite clusters from Bancroft-area workings are uncommon in the collector market — most material was extracted industrially with little regard for specimen quality — and pieces that preserve multiple crystals in their original spatial relationship are correspondingly more desirable than single crystals or massive material. The Cardiff Mine, one of the named uranium producers of Hastings County, operated in the Grenvillian pegmatite belt that defines the broader Bancroft uranium district. This cluster presents multiple uraninite crystals from Cardiff, offering the visual documentation of growth habit, crystal association, and matrix context that a single crystal cannot. The sooty to sub-metallic lustre, heavy specific gravity (nominally around 10.6–11 g/cm³ for pure material, reduced in natural specimens by alteration and inclusions), and robust radioactivity are all in evidence. A centrepiece-quality specimen for the Canadian radioactive mineral collection. Strongly radioactive. Canada domestic shipping only. Approx. specimen size: 25mm x 10mm x 7mm Approx. specimen weight: 11.47 grams Approx. specimen activity on an SE International Ranger EXP: 60000 CPM