Synchysite

Synchysite
A synchysite with unknown end-member composition
General
Category	Mineral
Formula (repeating unit)	Ca(REE)(CO3)2F
Strunz classification	5.BD.
Crystal system	Monoclinic and trigonal
Identification
Mohs scale hardness	4.5
References

Synchysite is a group of carbonate minerals. The three isostructural chemical end members are synchysite-(Ce), synchysite-(Nd) and synchysite-(Y). Huanghoite-(Ce) belongs to the group, but has a different symmetry and calcium is replaced by barium.