Reederite-(Y)

General Information: Chemical Formula:Na15Y2(CO3)9(SO3F)Cl Composition:(Molecular Weight = 1,197.26 gm)Sodium 28.80 % NaYttrium 14.85 % Y Carbon 9.03 % C Sulfur 2.68 % S Chlorine 2.96 % ClOxygen 40.09 % O Fluorine 1.59 % F  Empirical Formula: Na15Y2(CO3)9(SO3)FCl Environment:Inclusions in a trona-filled vug in a sodalite xenolith in syenite. IMA Status:Approved IMA Locality:Poudrette Quarry, Mont Saint-Hilaire, Rouville County, Quebec, Canada. Name Origin:For Dr. Richard J. Reeder, currently co-editor of the American Mineralogist.Physical Properties: Cleavage:[001] Perfect Color:yellow or orange brown. Density:2.91 Diaphaniety:Transparent Habits:Blocky - Crystal shape tends to be equant (e.g. feldspars)., Granular - Generally occurs as anhedral to subhedral crystals in matrix., Hardness:3-3.5 - Calcite-Copper Penny Luminescence:Non-fluorescent. Luster:Vitreous (Glassy) Streak:whiteMore details...