Ancylite-(La)

General Information:
 Chemical Formula:
Sr(La,Ce)(CO3)2(OH)·(H2O)
 Composition:
(Molecular Weight = 381.87 gm)
Strontium 22.95 % Sr
Lanthanum 27.28 % La
Cerium 9.17 % Ce
Hydrogen 0.79 % H 
Carbon 6.29 % C 
Oxygen 33.52 % O 
 Empirical Formula:
SrLa0.75Ce0.25(CO3)2(OH)·(H2O)
 Environment:
In hydrothermal veins in nepheline syenites.
 IMA Status:
Approved IMA (Dana # Added)
 Locality:
Marchenko Peak, Mount Kukisvumchorr, Khibina massif, Kola Peninsula, Russia.
 Name Origin:
Named for the composition and from the Greek "curved," in allusion to the rounded and distorted character of the crystals.
Physical Properties:
 Cleavage:
None
 Color:
yellow or yellowish brown.
 Density:
3.88
 Diaphaniety:
Translucent
 Habits:
Crystalline - Fine - Occurs as well-formed fine sized crystals., Pyramidal - Crystals are shaped like pyramids.,
 Hardness:
4-4.5 - Between Fluorite and Apatite
 Luminescence:
Non-fluorescent.
 Luster:
Vitreous (Glassy)
 Streak:
white
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