Tan crystals of the rare Zr mineral calciohilairite (right) associated to prismatic orange crystals of kuzmenkoite-Mn (left). From Lovozero Massif, Murmansk Oblast, Russian Federation. Ex Dr Hartel collection and Ex Excalibur collection. — Photo: David Hospital · CC BY-SA 4.0
Calciohilairite
Calciohilairite is an IMA-recognized mineral species in the silicate class, with the chemical formula CaZrSi₃O₉·3H₂O.
It crystallizes in the hexagonal crystal system (space group R32).
Key properties: Mohs hardness 4; specific gravity 2.68; Vitreous to pearly, dull if altered luster; optically uniaxial.
IMA symbol Chlr, IMA status: approved, named in 1984.
Found in miarolitic cavities in a peralkalic alaskitic border granite of a batholith (Liberty Bell Mountain, Washington, USA); in miarolitic cavities in a nepheline syenite sill (near Saint-Amable, Canada).
It is found associated with Microcline, quartz, albite, fluorite, chlorite, bastnÄasite, zircon, malachite (Liberty Bell Mountain, Washington, USA); nenadkevichite, rhodochrosite.
The name refers to the calcium content and relation to hilairite.