Vanadinite is an uncommon mineral, only occurring as the result of chemical alterations to a pre-existing material. It is therefore known as a secondary mineral. It is found in arid climates and forms by oxidation of primary lead minerals. Vanadinite is especially found in association with the lead sulfide, galena. Other associated minerals include wulfenite, limonite, and barite.
Cuprite, a copper mineral that was not known until 1845, is a secondary mineral of oxidizing sulfide-rich copper deposits. It's symmetry is in the Isometric system, but this specimen looks to have unequal axes of symmetry. This slightly more than one inch crystal is from Bisbee, Arizona. / Mineral Friends <3