For 10 points each, name this material whose "yellowcake" form was available in Niger as an ingredient of atomic weapons.
This material was first described by F.E.Brückmann in Jáchymov in what is now the Czech Republic, though it was officially discovered by Martin Klaproth in Johanngeorgenstadt. This material was mined in the Colorado Plateau alongside vanadium, while one modern source is run by Kazatomprom, which exploits deposits of this metal in Kazakhstan. The largest mill for this chemical is found at Key Lake, in the (*) Athabasca Basin of Saskatchewan, where this chemical is often mined in the form of ? pitchblende. For 10 points each, name this material whose "yellowcake" form was available in Niger as an ingredient of atomic weapons.
This material was first described by F.E.Brückmann in Jáchymov in what is now the Czech Republic, though it was officially discovered by Martin Klaproth in Johanngeorgenstadt.
{uranium}