Empressite Mineral Data

General Empressite Information

Chemical Formula:

AgTe

Composition:

Molecular Weight = 235.27 gm

Silver 46.31 % Ag

Tellurium 53.69 % Te

______

100.00 %

Empirical Formula:

Ag_1.01Te_0.99

Environment:

Low temperature gold-poor hydrothermal vein deposits.

IMA Status:

Valid Species (Pre-IMA) 1914

Locality:

Empress Josephine mine, Saguache County and Red Cloud mine, Bolder County, Colorado, USA. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Empressite + Pronunciation

Empressite Image

Images:

Empressite Tellurium

Comments: Bronze-colored microcrystals of empressite with bright native tellurium crystals.
Location: Rex mine, Boulder County, Colorado, USA. Scale: 1.9 x 1.4 x 0.7 cm.
© Richard Dale / Dale Minerals

Empressite Crystallography

Axial Ratios:

a:b:c =0.4418:1:0.2295

Cell Dimensions:

a = 8.882, b = 20.1, c = 4.614, Z = 16; V = 823.73 Den(Calc)= 7.59

Crystal System:

Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: Pmnb

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

By Intensity(I/I_o): 2.699(1)(241), 2.2205(0.34)(400), 3.3277(0.3)(240),3.1742(0.26)(141), 2.3138(0.23)(261), 3.8(0.21)(031), 2.1371(0.2)(271), 2.8873(0.15)(231), 4.012(0.15)(111),

Crystal Structure:

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Bindi L , Spry P G , Cipriani C , American Mineralogist , 89 (2004) p.1043-1047, Empressite, AgTe, from the Empress-Josephine Mine, Colorado, USA:, Composition, physical properties, and determination of the crystal structure

Physical Properties of Empressite

Cleavage:

None

Color:

Bronze, Light bronze.

Density:

7.5 - 7.6, Average = 7.55

Diaphaneity:

Opaque

Fracture:

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

Habit:

Compact - Occurs as a compact mass.

Hardness:

3.5 - Copper Penny

Luster:

Metallic

Streak:

grayish black

Optical Properties of Empressite

RL Anisotrophism:

Strong, gray to yellowish white to grayish blue.

RL Bireflectance:

Moderate to strong.

RL Color:

Grayish white with no internal reflections.

RL Pleochroism:

Very strong, in gray to creamy white.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Empressite in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
470 nm	40.10	45.80
550 nm	39.60	44.10
589 nm	39.40	43.20
650 nm	38.90	41.80

**Calculated Relative Intensity Colors of Empressite in Air**
Relative Intensity	0%	30%	60%	90%	100%	120%	150%	180%	210%	230%
R₁
R₂

Calculated Properties of Empressite

Electron Density:

Bulk Density (Electron Density)=6.38 gm/cc
note: Specific Gravity of Empressite =7.59 gm/cc.

Fermion Index:

Fermion Index = 0.04
Boson Index = 0.96

Photoelectric:

PE_Empressite= 321.24 barns/electron
U=PE_Empressite x rElectron Density=2,050.92 barns/cc.

Radioactivity:

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

Empressite Classification

Dana Class:

02.08.24.01 (02)Sulfides - Including Selenides and Tellurides

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

(02.08.24)Dana Group

02.08.24.01 Empressite AgTe Pmnb 2/m 2/m 2/m

Strunz Class:

02.CB.80 02 - SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulf

02.C - Metal Sulfides, M:S = 1:1 (and similar)

02.CB -With Zn, Fe, Cu, Ag, Au, etc

02.CB.80 Empressite AgTe Pmnb 2/m 2/m 2/m

Other Empressite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8, AmMin, v 89, p 1043) OPTIC PROP.(AmMin, v 89, p 1044)

See Also:

Links to other databases for Empressite :
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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Ask about Empressite here :
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Print or Cut-and-Paste your Empressite Specimen Label here :

Empressite

AgTe
Dana No: 02.08.24.01 Strunz No: 02.CB.80
Locality:

Notes: