Crandallite and Florensite-(Ce) from a Quartz Vein of the Area Zhelannoye Deposit (Subpolar Ural)

The article displays data on minerals of the plumbogummite group – crandallite and florencite-(Ce). Minerals were found on a fragment of a hematite aggregate recovered from the lower pinch out of a quartz vein of the Zone 25 occurrence. It is situated in close neighborhood to the known Zhelannoye deposit of vein quartz and rock crystals and the Au-Pd-REE ore deposit Chudnoye. Crandallite segregations are represented by two forms: rhombohedral crystals and spherulites. There are distinguished three generations of crandallite: the first one represented by rhombohedral crystals, the second – by crusts on the rhombohedron faces, the third – crandallite spherulites on the surface of rhombohedrons. The crusts, 150 µm thick, consist of four layers: REE-bearing crandallite, symplectite intergrowths of crandallite with florensite-(Ce), spherulites, and powdering of crandallite crystals. The first and second generations of the mineral were crystallized from solutions, the third resulted the redeposition. There are varying contents of Sr, Ba, REE, U, Fe, S, and Si admixtures in crandallite of different types.