Decrespignyite-(Y) Mineral Data

General Decrespignyite-(Y) Information

Chemical Formula:

(Y,REE)4Cu(CO3)4Cl(OH)5•2(H2O)

Composition:

Molecular Weight = 867.49 gm

Calcium 0.32 % Ca 0.45 % CaO

Lanthanum 0.32 % La 0.38 % La₂O₃

Praeseodymium 0.16 % Pr 0.19 % Pr₂O₃

Samarium 0.87 % Sm 1.00 % Sm₂O₃

Gadolinium 3.99 % Gd 4.60 % Gd₂O₃

Dysprosium 3.18 % Dy 3.65 % Dy₂O₃

Yttrium 32.08 % Y 40.74 % Y₂O₃

Holmium 2.28 % Ho 2.61 % Ho₂O₃

Erbium 2.12 % Er 2.43 % Er₂O₃

Terbium 0.37 % Tb 0.42 % Tb₂O₃

Copper 8.42 % Cu 10.55 % CuO

Hydrogen 1.17 % H 10.45 % H₂O

Carbon 5.22 % C 19.13 % CO₂

Neodymium 1.00 % Nd 1.16 % Nd₂O₃

Chlorine 2.90 % Cl 2.90 % Cl

- % Cl -0.65 % -O=Cl₂

Oxygen 35.60 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Y_3.13Gd_0.22Dy_0.17Ho_0.12Er_0.11Ca_0.07Nd_0.06Sm_0.05Tb_0.02La_0.02Pr_0.01Cu_1.15(CO₃)_3.77Cl_0.71 (OH)_0.29(OH)_5.63ï¿½2.07(H₂O)

Environment:

Supergene product with other Y-bearing copper minerals.

IMA Status:

Approved IMA 2002 (Dana # Added)

Locality:

Paratoo copper mine, Yunta, Olary Province, South Australia, Australia. Link to MinDat.org Location Data.

Name Origin:

Named for Robert James Champion de Crespigny (1950-), Chancellor of the University of Adelaide, Australia.

Synonym:

IMA2001-027

Decrespignyite-(Y) Image

Images:

Decrespignyite-(Y)

Comments: Blue, rounded aggregates of decrespignyite-(Y) on matrix.
Location: Paratoo copper mine, Yunta, Olary Province, South Australia, Australia. Scale: Picture size 2 mm.
© Thomas Witzke / Abraxas-Verlag

Decrespignyite-(Y) Crystallography

Axial Ratios:

a:b:c =0.3908:1:0.3772

Cell Dimensions:

a = 8.899, b = 22.77, c = 8.589, Z = 4; beta = 120.06° V = 1,506.31 Den(Calc)= 3.83

Crystal System:

Monoclinic Space Group: P 2, Pm or P 2/m

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 6.241(1)(021), 7.086(0.5)(011), 3.53(0.4)(022),2.143(0.3)(222,401), 7.463(0.3)(001), 22.79(0.3)(010), 3.336(0.3)(032), 4.216(0.3)(112),

Physical Properties of Decrespignyite-(Y)

Cleavage:

None

Color:

Intense royal blue, Turquoise blue.

Density:

3.64

Diaphaneity:

Transparent

Habit:

Efflorescences - Crystals covering matrix, generally produced from transpiro-evaporation.

Habit:

Globular - Spherical, or nearly so, rounded forms (e.g. wavellite).

Hardness:

4 - Fluorite

Luster:

Vitreous - Pearly

Streak:

pale blue

Optical Properties of Decrespignyite-(Y)

Gladstone-Dale:

CI meas= 0.115 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.159 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1621,KPDmeas= 0.1706,KC= 0.1928
Ncalc = 1.7 - 1.74

Optical Data:

Biaxial (-), a=1.604, g=1.638, bire=0.0340

Calculated Properties of Decrespignyite-(Y)

Electron Density:

Bulk Density (Electron Density)=3.41 gm/cc
note: Specific Gravity of Decrespignyite-(Y) =3.64 gm/cc.

Fermion Index:

Fermion Index = 0.05
Boson Index = 0.95

Photoelectric:

PE_{Decrespignyite-(Y)}= 149.05 barns/electron
U=PE_{Decrespignyite-(Y)} x r_electron= 508.51 barns/cc.

Radioactivity:

GRapi = 14,333.26 (Gamma Ray American Petroleum Institute Units)
Concentration of Decrespignyite-(Y) per GRapi unit = 69.77 (PPM)

Decrespignyite-(Y) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.

**Estimated Radioactivity from Decrespignyite-(Y)** - weak
Specimen Size Weight/Volume (Sphere) *	Calculated Activity Bequerols (Bq)	Calculated Activity Curies (Ci)	Estimated Activity GR(api)	Estimated Exposure (mRem**)/hr If Held in Hand For One Hour
1000 gm / 8.07 cm	321,156	8.68E-06	14,333.26	4.71
100 gm / 3.74 cm	32,116	8.68E-07	1,433.33	0.47
10 gm / 1.74 cm	3,212	8.68E-08	143.33	0.05
1 gm / 8.07 mm	321	8.68E-09	14.33	0.00
0.1 gm / 3.74 mm	32	8.68E-10	1.43	0.00
0.01 gm / 1.74 mm	3	8.68E-11	0.14	0.00
0.001 gm / 0.81 mm	0	8.68E-12	0.01	0.00

Weight of pure Decrespignyite-(Y) in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.64 gm/cc.*
Goverment Estimate of Average Annual Exposure ( 360 mRem) **
Note: 10 microsieverts/hr = 1 mRem/hr **
Max Permissable Adult Dose 50,000 mRem/yr (hands), 15,000 mRem/yr (eyes)
Lethal Dose LD(50) Exposure 400,000 to 500,000 mRem
Estimated Thorium Activity ( 0.71 % Th) From Sum REE Elements (14.29 % REE)

Decrespignyite-(Y) Classification

Dana Class:

16a.01.11.01 (16a)Carbonates - Hydroxyl or Halogen

(16a.01)in the Bastnasite/Shynchysite/Parasite Groups

(16a.01.11)Dana Group

16a.01.11.01 Decrespignyite-(Y)! (Y,REE)4Cu(CO3)4Cl(OH)5•2(H2O) P 2, Pm or P 2/m Mono

Strunz Class:

05.CC.35 05 - CARBONATES (NITRATES)

05.C - Carbonates without Additional Anions, with H2O

05.CC -With rare-earth elements (REE)

05.CC.35 Decrespignyite-(Y)! (Y,REE)4Cu(CO3)4Cl(OH)5•2(H2O) P 2, Pm or P 2/m Mono

Other Decrespignyite-(Y) Information

References:

NAME( AmMin, 87:1731) PHYS. PROP.(AmMin, 87:1731) OPTIC PROP.(AmMin, 87:1731)

See Also:

Links to other databases for Decrespignyite-(Y) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - Handbook of Mineralogy (UofA)
7 - MinDAT
8 - Mineralienatlas (Deutsch)
9 - Online Mineral Museum
10 - QUT Mineral Atlas
11 - Ruff.Info

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Decrespignyite-(Y)

(Y,REE)4Cu(CO3)4Cl(OH)5•2(H2O)
Dana No: 16a.01.11.01 Strunz No: 05.CC.35
Locality:

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