|
![Mineralogy Database Mineralogy Database](/images/Hedyphane_Crystal.gif) |
Alacranite Mineral Data
|
|
|
General Alacranite Information
|
Chemical Formula: |
As8S9 |
Composition: |
Molecular Weight = 887.97 gm |
|
Arsenic 67.50 % As |
|
Sulfur 32.50 % S |
|
______ |
|
100.00 % |
Empirical Formula: |
As8S9 |
Environment: |
Occurs as a cement in a sandy gravel (Uson caldera, USSR); in hydrothermal As-S veins (Alacran deposit, Chile). |
IMA Status: |
Approved IMA 1986 |
Locality: |
In the Uson caldera, Kamchatka, USSR. From the Alacran deposit, Pampa Larga, Chile. Link to MinDat.org Location Data. |
Name Origin: |
For the occurrence in the Alacran deposit, Chile. |
Name Pronunciation: |
Alacranite + Pronunciation |
Synonym: |
ICSD 42387 |
|
PDF 42-537 |
|
Alacranite Image |
Images:
|
|
Alacranite Crystallography
|
Axial Ratios: |
a:b:c =1.0355:1:0.9559 |
Cell Dimensions: |
a = 9.942, b = 9.601, c = 9.178, Z = 2; beta = 101.94° V = 857.12 Den(Calc)= 3.44 |
Crystal System: |
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2/c |
X Ray Diffraction: |
By Intensity(I/Io): 2.9319(1)(222), 5.8638(0.89)(111), 3.0493(0.87)(221),5.0927(0.71)(111), 3.2791(0.69)(022), 3.0719(0.68)(310), 4.0307(0.58)(112), |
|
Physical Properties of Alacranite
|
Cleavage: |
{???} Indistinct |
Color: |
Red, Orange yellow. |
Density: |
3.4 - 3.46, Average = 3.43 |
Diaphaneity: |
Transparent |
Habit: |
Equant Grains - Granular material with equel dimensions in x, y, and z. |
Habit: |
Euhedral Crystals - Occurs as well-formed crystals showing good external form. |
Hardness: |
1.5 - Between Talc and Gypsum |
Luster: |
Adamantine - Greasy |
Streak: |
orange |
|
Optical Properties of Alacranite
|
Optical Data: |
Biaxial (+), a=2.39, g=2.52, bire=0.1300 |
Pleochroism (x): |
orange yellow. |
Pleochroism (y): |
orange yellow. |
Pleochroism (z): |
orange yellow. |
RL Color: |
Light gray with rose-yellow internal reflections. |
Reflectivity |
Standardized Intensity (100%) Reflection Spectra of Alacranite in Air
λ |
R1 |
R2 |
![](../images/Reflect_scale_v.gif) |
∑ R1(λ) |
∑ R2(λ) |
400 nm |
13.00 |
14.00 |
![](../images/400nm.BMP)
![](../images/400nm.BMP) |
|
|
425 nm |
13.20 |
14.60 |
![](../images/425nm.BMP)
![](../images/425nm.BMP) |
450 nm |
13.30 |
14.80 |
![](../images/450nm.BMP)
![](../images/450nm.BMP) |
475 nm |
13.40 |
14.80 |
![](../images/475nm.BMP)
![](../images/475nm.BMP) |
500 nm |
13.30 |
14.50 |
![](../images/500nm.BMP)
![](../images/500nm.BMP) |
525 nm |
13.10 |
14.30 |
![](../images/525nm.BMP)
![](../images/525nm.BMP) |
550 nm |
13.20 |
14.50 |
![](../images/550nm.BMP)
![](../images/550nm.BMP) |
575 nm |
13.40 |
14.70 |
![](../images/575nm.BMP)
![](../images/575nm.BMP) |
600 nm |
13.50 |
14.80 |
![](../images/600nm.BMP)
![](../images/600nm.BMP) |
625 nm |
13.60 |
14.90 |
![](../images/625nm.BMP)
![](../images/625nm.BMP) |
650 nm |
13.70 |
15.00 |
![](../images/650nm.BMP)
![](../images/650nm.BMP) |
675 nm |
13.80 |
15.00 |
![](../images/675nm.BMP)
![](../images/675nm.BMP) |
700 nm |
13.90 |
15.10 |
![](../images/700nm.BMP)
![](../images/700nm.BMP) |
Calculated Relative Intensity Colors of Alacranite in Air
Relative Intensity |
0% |
70% |
100% |
140% |
210% |
280% |
350% |
420% |
490% |
560% |
630% |
670% |
R1 |
|
|
|
|
|
|
|
|
|
|
|
|
R2 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Calculated Properties of Alacranite
|
Electron Density: |
Bulk Density (Electron Density)=3.16 gm/cc note: Specific Gravity of Alacranite =3.44 gm/cc. |
Fermion Index: |
Fermion Index = 0.0024375405 Boson Index = 0.9975624595 |
Photoelectric: |
PEAlacranite = 49.28 barns/electron U=PEAlacranite x rElectron Density= 155.79 barns/cc. |
Radioactivity: |
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Alacranite is Not Radioactive |
|
Alacranite Classification
|
Dana Class: |
02.08.22.04 (02)Sulfides - Including Selenides and Tellurides |
|
(02.08)where Am Bn Xp, with (m+n):p=1:1 |
|
(02.08.22)Realgar Series |
|
02.08.22.01 Realgar AsS P 21/n 2/m |
|
02.08.22.02 Pararealgar AsS P 21/c 2/m |
|
02.08.22.03 Uzonite As4S5 P 21/m 2/m |
|
02.08.22.04 Alacranite As8S9 P 2/c 2/m |
Strunz Class: |
02.FA.20 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.FA -With As, (Sb), S |
|
02.FA.20 Alacranite As8S9 P 2/c 2/m |
|
Other Alacranite Information
|
References: |
NAME( AntBidBlaNic1) PHYS. PROP.(Am.Min.,v.73, p189, v 87, p 357, v 88, p 1796) OPTIC PROP.(Am.Min.,Vol.73,p189,1988, AntBidBlaNic1) |
See Also: |
Links to other databases for Alacranite :
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
Search for Alacranite using:
[AOL]
[Bing]
[Dog Pile]
[GeoScienceWorld]
[HotBot]
[Ixquick]
[Lycos]
[MAMMA]
[Scirus]
[Teoma]
[WebCrawler]
[Wikipedia]
[YAHOO]
Visit our Advertisers for Alacranite :
Ask about Alacranite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in
Espaņol
Print or Cut-and-Paste your Alacranite Specimen Label here :
Alacranite
As8S9
Dana No: 02.08.22.04 Strunz No: 02.FA.20
Locality:
Notes:
|
|
|
|
|
|
Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.