Cronusite Mineral Data

General Cronusite Information

Chemical Formula:

Ca0.2(H2O)2CrS2

Composition:

Molecular Weight = 161.98 gm

Calcium 4.95 % Ca

Chromium 32.10 % Cr

Hydrogen 2.61 % H

Sulfur 39.59 % S

Oxygen 20.74 % O

______

100.00 %

Empirical Formula:

Ca_0.2(H₂O)_2.1CrS₂

Environment:

Derived from the weathering of caswellsilverite and disseminated in enstatite. Close to schöllhornite.

IMA Status:

Approved IMA 2002 (Dana # Added)

Locality:

Norton County enstatite achondrite meteorite, Kansas, USA. Link to MinDat.org Location Data.

Name Origin:

Name derived from the Greek Titan "Cronos" and alludes to the combined meteor-terrestrial origin where cronusite is derived from terretrial weathering of meteoric minerals.

Synonym:

IMA1999-018

Cronusite Image

Images:

Cronusite

Comments: Light gray grain of cronusite. Polished section (from microprobe analysis) in reflected light.
Location: Enstatite meteorite, Norton Co., Kansas, USA. Scale: Picture size 0.18 mm.
© Thomas Witzke / Abraxas-Verlag

Cronusite Crystallography

Axial Ratios:

a:c = 1:10.00901

Cell Dimensions:

a = 3.326, c = 33.29, Z = 3; V = 318.93 Den(Calc)= 2.53

Crystal System:

TrigonalSpace Group: Rm, R 3m or R 32

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

By Intensity(I/I_o): 11.1(1)(003), 2.719(0.5)(104), 2.18(0.49)(1.1.10),2.464(0.4)(107), 3.7(0.4)(009), 5.56(0.1)(006),

Physical Properties of Cronusite

Cleavage:

{001} Perfect

Color:

Coal black.

Density:

2.51

Diaphaneity:

Opaque

Fracture:

Sectile - Curved shavings or scrapings produced by a knife blade, (e.g. graphite).

Habit:

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

Habit:

Inclusions - Generally found as inclusions in other minerals.

Hardness:

1.5 - Between Talc and Gypsum

Luster:

Sub Metallic

Streak:

black

Optical Properties of Cronusite

RL Anisotrophism:

Strong.

RL Bireflectance:

Strong.

RL Color:

Gray with no internal reflections.

RL Pleochroism:

In gray polarization colors.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Cronusite in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
460 nm	14.40	15.80
540 nm	15.70	17.60
580 nm	16.20	18.20
640 nm	16.60	18.60

**Calculated Relative Intensity Colors of Cronusite in Air**
Relative Intensity	0%	70%	100%	140%	210%	280%	350%	420%	490%	560%	610%
R₁
R₂

Calculated Properties of Cronusite

Electron Density:

Bulk Density (Electron Density)=2.53 gm/cc
note: Specific Gravity of Cronusite =2.53 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Cronusite= 9.72 barns/electron
U=PE_Cronusite x rElectron Density= 24.59 barns/cc.

Radioactivity:

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

Cronusite Classification

Dana Class:

02.09.17.03 (02)Sulfides - Including Selenides and Tellurides

(02.09)where Am Bn Xp, with (m+n):p=1:1

(02.09.17)Caswellsilverite Group

02.09.17.01 Caswellsilverite NaCrS2 R 3m 3 2/m

02.09.17.02 Schollhornite Na0.3CrS2•(H2O) R 3m ? 3m

02.09.17.03 Cronusite! Ca0.2(H2O)2CrS2 Rm, R 3m or R 32 Trig

Strunz Class:

02.FB.05 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf

02.F - Sulfides of Arsenic, Alkalies; Sulfides with Halide, Oxide, Hydroxide, H2O

02.FB -With Alkalies (without Cl, etc.)

02.FB.05 Caswellsilverite NaCrS2 R 3m 3 2/m

02.FB.05 Schollhornite Na0.3CrS2•(H2O) R 3m ? 3m

02.FB.05 Cronusite! Ca0.2(H2O)2CrS2 Rm, R 3m or R 32 Trig

Other Cronusite Information

References:

NAME( AmMin, Vol 87, p 1510) PHYS. PROP.(AmMin, Vol 87, p 1510) OPTIC PROP.(AmMin, Vol 87, p 1510)

See Also:

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

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Ask about Cronusite here :
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Print or Cut-and-Paste your Cronusite Specimen Label here :

Cronusite

Ca0.2(H2O)2CrS2
Dana No: 02.09.17.03 Strunz No: 02.FB.05
Locality:

Notes: