Category Phosphate mineral Crystal system Orthorhombic | Formula
(repeating unit) Na8Ce(La,REE)2(PO4)6 Space group Pnma | |
Crystal class Dipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m) Unit cell a = 18.466, b = 16.011
c = 7.027 [Å] (approximated)
Z = 4 | ||
Dyrnaesite-(La) is a recently described rare earth phosphate mineral with the formula Na8Ce4+(La,REE)2(PO4)6. Dyrnaesite-(La) is related to vitusite-(Ce), another rare earth phosphate mineral. It comes from lujavrite, a type of alkaline syenite rock, of South Greenland. Dyrnaesite-(La) is one of few known minerals with essential tetravalent cerium, the other two being cerianite-(Ce) and stetindite.
References
Dyrnaesite-(La) Wikipedia(Text) CC BY-SA