Near perfect formation of (blue) Decrespignyite-(Y) crystals creating botryoidal type formations with a small amount of (grey) Kamphaugite-(Y) — Photo: Mark Trevor Willoughby · CC BY-SA 4.0
Kamphaugite-(Y)
Kamphaugite-(Y) is an IMA-recognized mineral species in the carbonate class, with the chemical formula CaY(CO₃)₂(OH)·H₂O.
It crystallizes in the tetragonal crystal system (space group P4_12_12).
Key properties: Mohs hardness 2–3; specific gravity 3.19; White streak; Vitreous luster; optically uniaxial.
IMA symbol Khg-Y, IMA status: approved, named in 1987.
A late, low-temperature mineral formed in a contact-metamorphic skarn (Hørtekollen deposit, Norway); in metasomatically altered alkali granite (Kazakhstan); in a quartz–barite vein in a carbonatized volcano (South Africa).
It is found associated with Kuliokite-(Y) (Norway); gagarinite (Kazakhstan); kainosite-(Y), hingganite-(Y) (Cal Francese, Sardinia, Italy); caysichite-(Y), donnayite-(Y).
The mineral was named to honor Erling Kamphaug (1931–), Norwegian mineral collector, who supplied the first specimens.