THE MINERAL RHABDOPHANE



Rhabdophane is one of several rare earth phosphate minerals. Xenotime - (Y), monazite, churchite - (Y), florencite and belovite - (Ce) are a few of the more common ones. Although not very common, rhabdophane is common enough to be considered an ore of cerium. Rhabdophane is a mineral that forms from the alteration of rare earth igneous minerals and as a primary mineral in carbonatites and in a few rare hydrothermal veins. Its most noticeable feature is it greasy luster and botryoidal habit. Rhabdophane was named for its spectral signature which reveals the tell-tail spectral lines of its rare earth elements. Rhabdophane is basically Greek for "rods appearing".

Rhabdophane is actually a collection of three officially recognized minerals that are distinguished by their percentages of rare earth elements. Each is named for the rare earth element that composes the highest percentage of rare earth elements in that particular mineral. The three minerals are Rhabdophane - (Ce), Rhabdophane - (La), Rhabdophane - (Nd) All are very similar and difficult to distinguish. Most rhabdophane specimens are rhabdophane - (Ce) and this is most likely the mineral that is referred to when specimens are labeled simply as "rhabdophane".

Rhabdophane lends its name to a small group of phosphates. All members of the Rhabdophane Group are hexagonal or pseudo-hexagonal and have a general formula of (X)PO4 - 1-2H2O. The X can be either calcium, cerium, lead, lanthanum, neodymium, thorium, iron and uranium. Some sulfate ions, (SO4), can replace a portion of the phosphate ions, (PO4).

These are the members of the Rhabdophane Group:


PHYSICAL CHARACTERISTICS OF RHABDOPHANE:

 

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