Caysichite-(Y) Mineral Data

General Caysichite-(Y) Information

Chemical Formula:

Y2(Ca,Gd)2Si4O10(CO3)3(H2O,O,OH)•3H20

Composition:

Molecular Weight = 819.17 gm

Calcium 8.81 % Ca 12.32 % CaO

Gadolinium 3.84 % Gd 4.43 % Gd₂O₃

Yttrium 21.71 % Y 27.57 % Y₂O₃

Silicon 13.71 % Si 29.34 % SiO₂

Hydrogen 0.86 % H 7.69 % H₂O

Carbon 4.88 % C 17.89 % CO₂

Oxygen 46.19 % O

______ ______

100.00 % 99.23 % = TOTAL OXIDE

Empirical Formula:

Y₂Ca_1.8Gd_0.2Si₄O₁₀(CO₃)_3.33(OH)_0.33•3.33(H₂O)

Environment:

Occurs in granite pegmatite lining cavities.

IMA Status:

Approved IMA 1974

Locality:

Evans-Lou feldspar mine, Portland West Township, Quebec, Canada. Link to MinDat.org Location Data.

Name Origin:

Named for the composition (Ca, Y, Si, CO3).

Synonym:

ICSD 200418

IMA1973-044

PDF 26-1394

Caysichite-(Y) Image

Images:

Caysichite-(Y)

Comments: Brownish inclusions of caysichite-(Y) with white tengerite-(Y) rims.
Location: Mt. Ploskaja, Keivi, Kola, Russia. Scale: Sample Size 2.5x3 cm.
© Diederik Visser

Caysichite-(Y) Crystallography

Axial Ratios:

a:b:c =0.9534:1:0.6982

Cell Dimensions:

a = 13.3, b = 13.95, c = 9.74, Z = 4; V = 1,807.11 Den(Calc)= 3.01

Crystal System:

Orthorhombic - Pyramidal H-M Symbol (mm2) Space Group: Ccm21

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

By Intensity(I/I_o): 6.93(1), 3.32(0.9), 4.38(0.6),

Physical Properties of Caysichite-(Y)

Cleavage:

{010} Indistinct

Color:

Colorless, Green, Greenish yellow, White, Light yellow.

Density:

3.03

Diaphaneity:

Transparent

Habit:

Pulverulent - Forms a loose, poorly-coherent powdery mass.

Habit:

Reniform - "Kidney like" in shape (e.g.. hematite).

Habit:

Stalactitic - Shaped like pendant columns as stalactites or stalagmites (e.g. calcite).

Hardness:

4.5 - Between Fluorite and Apatite

Luminescence:

Cathodoluminescence.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Caysichite-(Y)

Gladstone-Dale:

CI meas= 0.011 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.004 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2022,KPDmeas= 0.2009,KC= 0.2031
Ncalc = 1.61 - 1.62

Optical Data:

Biaxial (-), a=1.586-1.589, b=1.614-1.616, g=1.621-1.626, bire=0.0350-0.0370, 2V(Calc)=52-60, 2V(Meas)=61.

Calculated Properties of Caysichite-(Y)

Electron Density:

Bulk Density (Electron Density)=2.93 gm/cc
note: Specific Gravity of Caysichite-(Y) =3.01 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_{Caysichite-(Y)}= 53.39 barns/electron
U=PE_{Caysichite-(Y)} x r_electron= 156.54 barns/cc.

Radioactivity:

GRapi = 3,989.05 (Gamma Ray American Petroleum Institute Units)
Concentration of Caysichite-(Y) per GRapi unit = 250.69 (PPM)

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

**Estimated Radioactivity from Caysichite-(Y)** - mild
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 / 8.59 cm	85,999	2.32E-06	3,989.05	1.31
100 gm / 3.99 cm	8,600	2.32E-07	398.90	0.13
10 gm / 1.85 cm	860	2.32E-08	39.89	0.01
1 gm / 8.59 mm	86	2.32E-09	3.99	0.00
0.1 gm / 3.99 mm	9	2.32E-10	0.40	0.00
0.01 gm / 1.85 mm	1	2.32E-11	0.04	0.00
0.001 gm / 0.86 mm	0	2.32E-12	0.00	0.00

Weight of pure Caysichite-(Y) in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.01 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 ( 0.19 % Th) From Sum REE Elements ( 3.84 % REE)

Caysichite-(Y) Classification

Dana Class:

70.01.02.02 (70)Inosilicate Column or Tube Structures

(70.01)with columnar silicate units

(70.01.02)Double crankshaft chains

70.01.02.01 Narsarsukite Na2(Ti,Fe)Si4(O,F)11 I 4/m 4/m

70.01.02.02 Caysichite-(Y) Y2(Ca,Gd)2Si4O10(CO3)3(H2O,O,OH)•3H20 Ccm21 mm2

70.01.02.03 Charoite K5Ca8(Si6O15)2(Si2O7)Si4O9(OH)•3(H2O) P*/4 ((pseudo Ortho) 2/m

Strunz Class:

09.DJ.15 09 - SILICATES (Germanates)

09.D - Inosilicates* Structural terminology according to Liebau (1985)

09.DJ -Inosilicates with 4-periodic double and triple chains

09.DJ.15 Caysichite-(Y) Y2(Ca,Gd)2Si4O10(CO3)3(H2O,O,OH)•3H20 Ccm21 mm2

Other Caysichite-(Y) Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Caysichite-(Y) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (UofA)
9 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info
14 - WWW-MINCRYST

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Caysichite-(Y)

Y2(Ca,Gd)2Si4O10(CO3)3(H2O,O,OH)•3H20
Dana No: 70.01.02.02 Strunz No: 09.DJ.15
Locality:

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