Crawfordite Mineral Data

General Crawfordite Information

Chemical Formula:

Na3Sr(PO4)(CO3)

Composition:

Molecular Weight = 311.57 gm

Sodium 22.14 % Na 29.84 % Na₂O

Strontium 28.12 % Sr 33.26 % SrO

Phosphorus 9.94 % P 22.78 % P₂O₅

Carbon 3.85 % C 14.13 % CO₂

Oxygen 35.95 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₃Sr(PO₄)(CO₃)

Environment:

In hyperagpatic pegmatites.

IMA Status:

Approved IMA 1994

Locality:

Mount Koashava, Khibini alkaline massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.

Name Origin:

For the Scottish doctor and chemist, Dr. A. Crawford (1748-1795).

Synonym:

ICSD 39559

IMA1993-030

PDF 47-1853

Crawfordite Crystallography

Axial Ratios:

a:b:c =1.3684:1:0.787

Cell Dimensions:

a = 9.178, b = 6.707, c = 5.279, Z = 2; beta = 89.163° V = 324.92 Den(Calc)= 3.18

Crystal System:

Monoclinic - Sphenoidal H-M Symbol (2) Space Group: P 2₁

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

By Intensity(I/I_o): 2.172(1), 2.708(1), 2.648(0.9),

Physical Properties of Crawfordite

Cleavage:

None

Color:

Colorless, White.

Density:

3.05 - 3.08, Average = 3.06

Diaphaneity:

Transparent to translucent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Hardness:

3 - Calcite

Luminescence:

Fluorescent, Short UV=bright greenish yellow.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Crawfordite

Gladstone-Dale:

CI meas= -0.017 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.02 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1729,KPDmeas= 0.1793,KC= 0.1764
Ncalc = 1.54 - 1.56

Optical Data:

Biaxial (-), a=1.52, b=1.564, g=1.565, bire=0.0450, 2V(Calc)=16, 2V(Meas)=20. Dispersion not discernible.

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Crawfordite

Electron Density:

Bulk Density (Electron Density)=2.91 gm/cc
note: Specific Gravity of Crawfordite =3.07 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Crawfordite= 32.16 barns/electron
U=PE_Crawfordite x rElectron Density= 93.64 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Crawfordite is Not Radioactive

Crawfordite Classification

Dana Class:

43.02.01.04 (43)Compound Phosphates, etc.

(43.02)(Anhydrous Normal Compound Anions)

(43.02.01)Bradleyite Group

43.02.01.01 Bradleyite Na3Mg(PO4)(CO3) P 2₁/m 2/m

43.02.01.02 Sidorenkite Na3Mn(PO4)(CO3) P 2₁/m 2/m

43.02.01.03 Bonshtedtite Na3Fe(PO4)(CO3) P 2₁/m 2/m

43.02.01.04 Crawfordite Na3Sr(PO4)(CO3) P 2₁ 2

Strunz Class:

05.BF.10 05 - CARBONATES (NITRATES)

05.B - Carbonates with additional anions, without H2O

05.BF -With (Cl), SO4, PO4, TeO3

05.BF.10 Bonshtedtite Na3Fe(PO4)(CO3) P 2₁/m 2/m

05.BF.10 Crawfordite Na3Sr(PO4)(CO3) P 2₁ 2

05.BF.10 Bradleyite Na3Mg(PO4)(CO3) P 2₁/m 2/m

05.BF.10 Sidorenkite Na3Mn(PO4)(CO3) P 2₁/m 2/m

Other Crawfordite Information

References:

NAME( MinRec) PHYS. PROP.(37th List of New Min.,Min. Mag.,1996) OPTIC PROP.(MinRec)

See Also:

Links to other databases for Crawfordite :
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 (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info

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Print or Cut-and-Paste your Crawfordite Specimen Label here :

Crawfordite

Na3Sr(PO4)(CO3)
Dana No: 43.02.01.04 Strunz No: 05.BF.10
Locality:

Notes:

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