
General Information:

Chemical Formula:
(Ca,Na)2(Y,REE)3Si6O18·2(H2O)

Composition:
(Molecular Weight = 872.18 gm)
La,Ce,Pr,Nd,Sm,12.38 %
RESodium 1.32 %
NaCalcium 6.89 %
CaYttrium 22.94 %
Y Silicon 19.32 %
SiHydrogen 0.46 %
H Oxygen 36.69 %
O 
Empirical Formula:
Ca1.5Na0.5Y2.25REE0.75Si6O18·2(H2O)

Environment:
Cyclosilicate with structural similarites to kainosite-(Y) and leifite. Found in an aplite-pegmatite lens.

Locality:
Strange Lake peralkaline complex on the Quebec-Labrador border, Canada.

Name Origin:
For Richard Geren (1917-), former executive vice-president of the Iron Ore Company of Canada. Mr. Geren initiated and supported the exploration program of the Strange Lake deposit.
Physical Properties:

Cleavage:
[101] Indistinct

Color:
white or cream white.

Density:
3.3 - 3.52, Average = 3.41

Diaphaniety:
Translucent

Habits:
Microscopic Crystals - Crystals visible only with microscopes., Anhedral Grains - Granular minerals without the expression of crystal shapes,

Hardness:
5 - Apatite

Luminescence:
Non-fluorescent.

Luster:
Vitreous (Glassy)

Streak:
white
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