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Formula: (Sr,Ce,La)(Ca,Na)(CO3)2
Anhydrous normal carbonate, strontium-,
cerium- and lanthanum- bearing
mineral
Crystal System: Orthorhombic
Specific gravity: 3.33 to 3.45 measured, 3.53 calculated
Hardness: 3
Streak: White
Colour: Colourless; white, yellow, yellowish green, rose or brown if altered
Solubility: Easily soluble in dilute hydrochloric acid
Weakly RADIOACTIVE
Environments
Localities
At the Central Khanneshin deposit, Khanneshin complex, Reg District, Helmand, Afghanistan, carbocernaite is
associated with dolomite, baryte,
chlorite, mckelveyite-(Y),
calkinsite-(Ce) and
khanneshite
(HOM).
At the Sturgeon Narrows Alkaline Complex, Squash Lake Area, Kenora District, Ontario, Canada, carbocernaite has
been identified from the east side of the Narrows. Data for carbocernaite from this locality this are in close
agreement with the data published for carbocernaite from the type locality in the Kola Peninsula, but this
carbocernaite contains significant amounts of fluorine, is a more
strontium-rich variety and contains no sodium or
barium.
Carbocernaite occurs as distinct layers and clusters in an albite -
biotite - calcite
carbonatite. The mineral is closely associated with purple
fluorite and calcite and together
they give the rock a definite gneissic appearance. The layers of
carbocernaite are even more distinct on the weathered surface because the mineral is more resistant to
weathering than the surrounding calcite. Associated minerals include
pyrite, quartz,
baryte, galena,
chalcopyrite and minor amounts of
ancylite. The carbocernaite varies from pale pink to brick red in
colour, due to admixed iron oxide in the mm-sized grains
(CM 11.812-818).
At Sarnu-Dandali, Malani Igneous Province, Barmer District, Jodhpur Division, Rajasthan, India, carbocernaite
occurs exsolved from calcite and in a
carbonatite dike in
fenitised dark-coloured
nephelinite
(HOM).
At the Carbonatite Stock in the vicinity of Tul'ilukht Bay,
Khibiny Massif, Murmansk Oblast, Russia, hexagonal
prismatic pseudomorphs of
ancylite-(Ce) or
synchysite-(Ce), strontianite
and baryte after burbankite and
carbocernaite occur
(MM 62.2.225-250).
At the type locality, the Vuoriyarvi alkaline-ultrabasic massif, Northern Karelia, Murmansk Oblast, Russia,
carbocernaite occurs in dolomite -
calcite carbonatite
veins 0.5 to 1 m in width, in pyroxenites and
ijolites, as accessory grains and as crystals on walls of cavities,
closely associated with chlorite and
ankerite. Other associated minerals include
sphalerite, galena,
pyrite and baryte, and in the
cavities
alstonite, anatase,
quartz and zeolites
(AM 46.1202).
At Bear Lodge Mining District, Crook County, Wyoming, USA, zoned crystals of carbocernaite occur in
hydrothermally reworked burbankite- and
fluorapatite- bearing calcite
carbonatite. The carbocernaite is paragenetically
associated with pyrite,
strontianite, baryte,
ancylite-(Ce) and late-stage
calcite. It is assumed to have precipitated from sulphate-bearing fluids
derived from an external source and enriched in sodium, calcium, strontium,
barium and rare-earth elements through dissolution of the
primary calcite and
burbankite.
The crystals of carbocernaite show complex zoning patterns arising from significant variations in the content
of all major cations
(AM 102.1340-1352).
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