Crystal system Monoclinic | Formula(repeating unit) Ce4FeTi6O18(OH)2 Space group C2/m | |
Crystal class Prismatic (2/m)(same H-M symbol) Unit cell a = 5.29, b = 14.58c = 5.23 [Å]; β = 97.23° (approximated); Z = 1 | ||
Anzaite-(Ce) is a rare earth element (REE) oxide mineral with the formula Ce4Fe2+Ti6O18(OH)2. An example of chemically related mineral is lucasite-(Ce), although it contains no iron. Cerium in anzaite-(Ce) is mainly substituted by neodymium, lanthanum, calcium and praseodymium. Titanium is substituted by niobium. Trace elements include thorium. The mineral is monoclinic, space group C2/m. Anzaite-(Ce) is hydrothermal mineral found in a carbonatite from the mineralogically-prolific Kola Peninsula. The mineral name honors Anatoly N. Zaitsev, who is known for studies of carbonatites and REE.
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Occurrence and association
Parent rocks for anzaite-(Ce) are silicocarbonatites of the Afrikanda alkali-ultramafic massif. These rocks underwent hydrothermal reworking, that beside anzaite-(Ce) produced also calcite, clinochlore, hibschite and titanite in expense of primary minerals.
Crystal structure
The crystal structure of anzaite-(Ce) characterizes in:
The disordered sites are located on the (010) planes, separated by ordered domains containing REE, VITi (octahedral) and two oxide-anion sites.