Images
Formula: NaNd(SO4)2(H2O)
Sulphate, neodymium-bearing mineral
Crystal System: Trigonal
Specific gravity: 3.436 calculated
Hardness: 2½ to 3
Streak: White
Colour: Colourless
Luminescence: No fluorescence under UV
Environments
Sedimentary environments
Hydrothermal environments
Chinleite-(Nd) is a new mineral, approved in 2022 and to date (August 2023) it has been reported only from the Red
Canyon Mining District (two localities).
Localities
At the type locality, the Markey mine, Red Canyon Mining District, San Juan County, Utah, USA, the
uranium deposits occur within the Shinarump member of the Upper
Triassic (237 to 201.4 million years ago) Chinle Formation in channels incised into the reddish-brown
siltstones of the underlying Lower Triassic (251.9 to 247.2 million
years ago) formation. The Shinarump member consists of medium- to coarse-grained
sandstone,
conglomeratic
sandstone beds, and thick
siltstone lenses. Ore minerals, such as
uraninite, montroseite and
coffinite, were deposited as replacements of wood and other organic
material and as disseminations in the enclosing sandstone.
Since the mine closed in 1982, oxidation of primary ores in
the humid underground environment has produced a variety of
secondary minerals, mainly carbonates and sulphates, as
efflorescent crusts on the surfaces of mine walls.
Chinleite-(Nd) is a very rare mineral in the secondary
mineral assemblage. It occurs on asphaltite in association with
gypsum and natrozippeite, as
prisms up to about 0.3 mm in length and 0.1 mm in diameter. The rare-earth elements probably existed in the
sandstones of the Chinle Formation prior to the deposition of the
uranium ores
(CJMP 61.2.411-418).
Back to Minerals