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Yingjiangite

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Yingjiangite
General
CategoryMineral
Formula
(repeating unit)
K2Ca(UO2)7(PO4)4(OH)6 · 6H2O
IMA symbolYin[1]
Strunz classification8.EC.10
Dana classification42.6.12.1
Crystal systemOrthorhombic
Crystal classDipyramidal
H-M Symbol: mmm
(2/m 2/m 2/m)
Unit cell3,747.21
Identification
ColorYellow, golden yellow
CleavageNone observed
TenacityBrittle
Mohs scale hardness3 - 4
LusterSubadamantine, subvitreous, rsinous
StreakYellow to pale yellow
Specific gravity4.15
Density4.15
Optical propertiesBiaxial (-)
Refractive indexnα = 1.666 - 1.669
nβ = 1.692 - 1.703
nγ = 1.707 - 1.710
Birefringence0.041
PleochroismVisible
2V angleMeasured: 36°- 38°
Calculated: 36°
Dispersionr > v or r < v
ExtinctionParallel
Ultraviolet fluorescenceFluorescent
Common impuritiesNa, Mg, Mn, Fe, Ti, Si
Other characteristicsRadioactive

Yingjiangite is a mineral named after its type locality in the Yingjiang county in 1990. It is a member of the phosphuranylite group, although the species was doubted by two geologists. It is easily confused with phosphuranylite, though the two geologists (José Moacyr Vianna Coutinho and Daniel Atencio) claim that the mineral might be identical to it, even though yingjiangite was approved in 1989-1990 by the IMA.[2]

Properties

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This mineral has pleochroic attributes, which is an optical phenomenon that makes the mineral seem to be a different color depending on the axis it is inspected on. On the x axis, the mineral seems to be almost colorless, on the y it is pale yellow, and on the z it can be seen as a yellow mineral.[2] It is also fluorescent, meaning that it emits light when exposed to a certain type of light (in most cases ultraviolet), or either when it absorbs electromagnetic radiation. The fluorescent attribute of is due to the mineral being uranium based. Both under short and long UV light, it emits a weak yellow green light.[3] Yingjiangite grows in acicular crystals up to a millimeter. It forms aggregates, made of clusters or several individual crystals. It has a fine-grained coating and yellow crusts. A common finding place for the mineral is in uranium deposits, especially in oxidized zones, as it is a uranium and oxygen-based mineral.[2] It is a secondary product in these mines, which in most of the cases contain uraninite and uranothorite. Yingjiangite mostly consists of uranium (63.90%) and oxygen (25.77%), but otherwise includes phosphorus (4.75%), potassium (4.50%), hydrogen (0.70%) and calcium (0.38%). Due to the high uranium concentration of the mineral, it has a very strong, 4,679,034.10 radioactivity measured in Gamma Ray American Petroleum Institute Units. The concentration per GRapi unit of the mineral is 213.72.[3]

References

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  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b c "Yingjiangite". www.mindat.org. Retrieved 2021-09-17.
  3. ^ a b "A to Z List". webmineral.com. Retrieved 2021-09-17.