Parisite-(La)
Parisite-(La) is a rare earth fluorocarbonate mineral with the chemical formula CaLa2(CO3)4F2. It is the lanthanum-dominant analogue of parisite-(Ce). It belongs to the parisite group of minerals.
Parisite-(La) is typically found in hydrothermal veins and carbonatites. It occurs as small, often metamict, crystals. Metamictization, or metamict state, refers to the destruction of the crystalline structure of a mineral due to the radiation damage from included radioactive elements like thorium or uranium. This damage makes the mineral amorphous.
Distinguishing parisite-(La) from other members of the parisite group, such as parisite-(Ce), requires chemical analysis to determine the dominant rare earth element present. X-ray diffraction can confirm the mineral's structure and identify it within the group.
The mineral is named for its relationship to parisite and its lanthanum-dominant composition.