Ex Ron Waddell (found 1975). MOB Coll. Orange/brown rinkite prisms to ~ 3¼ mm embedded in very dark purple fluorite with pale greenish fluorapatite. Some of the rinkite appears to be well terminated. There are several examples of terminated sprays on the specimen, This is part of [1] – which see for comments on the ID. Most of the apatite prisms (to ~ 15 mm long and as much as 6+ mm in diameter) are broken or embedded. For an example of an intact termination see [2] . Modified by CombineZP — Photo: Modris Baum · CC0
Rinkite-(Ce)
Rinkite-(Ce) is an IMA-recognized mineral species in the silicate class, with the chemical formula (Ca₃REE)Na(NaCa)Ti(Si₂O₇)₂(OF)F₂.
It crystallizes in the monoclinic crystal system. It is a member of the Seidozerite-Rinkite structural group.
Key properties: Mohs hardness 4–5; specific gravity 3.18–3.44; Pale yellow, grayish brown, white streak; Vitreous on fractures, resinous to greasy on cleavages luster; optically biaxial.
IMA symbol Rin-Ce, IMA status: approved, named in 1884.
Characteristic of some nepheline syenites and related pegmatites.
It is found associated with Arfvedsonite, aegirine, eudialyte, steenstrupine, leucophanite, wöhlerite, rosenbuschite, sodalite.
The name refers to H. Rink, former Director of Danish-Greenland commerce. Suffix is the dominant REE.