Tengchongite	IMA-A 1984-031
Uranium	49.3.1.2 (Dana Classification Number)
(No Images)	6/G.06-20 (Strunz ID)

Property	Data	Remarks
Named for:	Tengchong Co., Yunnan, China, its type locality
Alternate     Name(s):
Mineral Class:	Sulphates, Chromates, Molybdates - - Deloryite - Iriginite series
Chemical     Formula:	CaO(UO3)6(MoO3)2 . 12H2O
Chemical     Composition:	Calcium: (Ca) 1.76% Hydrogen: (H) 1.06% Oxygen: (O) 26.01% Molybdenum: (Mo) 8.43% Uranium: (U) 62.74%	by weight
Molecular     Weight:	2,276.30	daltons (amu)
Specific     Radioactivity:	(All radiation is for a 1 gram, fully aged specimen) Specific Activity Dose Rate Becquerels Curies milliRems/hour microSieverts/hour 1.12306 × 1005 3.04 × 10-06 1.51 150.77 Estimated Average Annual Exposure: 360 mRem (3.6 milliSieverts)
Crystalography:	System: Orthorhombic - Disphenoidal Axial Ratios: a:b:c = 1.1972:1:1.3582 Cell Dimensions: a = 15.616, b = 13.043, c = 17.716, Z = 4; V = 3,608.39 Den(Calc) = 4.19 H-M Symbol: 2 2 2 Space Group: A2122 X Ray Diffraction: By Intensity(I/Io): 8.84(1) 3.17(0.8) 3.38(0.7)
Habit:
Cleavage:	[001] [010] [100]
Fracture:
Moh's     Hardness:	2 - 2.5
Density:	4.25	grams/cm3
Color:	Yellow
Streak:	Light yellow
Luster:	Vitreous
Diaphaneity:	Transparent to Translucent
Pleochroism:	(x): (y:) (z:)
Ultra Violet     Fluorescence:	Long Wave: Short Wave:
Magnetism:	Non-magnetic
Occurance:
Associated     Minerals:	Autunite, Calcurmolite, Studtite, Uranothorite, Uraninite, Yingjiangite Mineral   -   both sites Minerals   -   Uranium & Thorium mineral links	These are minerals known to be found with Tengchongite
Locations:	Extremely rare Tengchongite Locations
Notes:	Strongly radioactive a- and b-particles, g-rays.