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Olsacherite
A valid IMA mineral species
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About Olsacherite
Juan A. Olsacher
Formula:
Pb2(Se6+O4)(SO4)
Colour:
Colorless
Lustre:
Vitreous, Dull
Hardness:
3 - 3½
Specific Gravity:
6.55 (Calculated)
Crystal System:
Orthorhombic
Name:
Named in honor of Juan Augusto Olsacher (1903 - 16 May 1964), Argentine mineralogist, professor, and chair of mineralogy at the University of Córdoba. An expert on selenium minerals in Argentina, he discovered and described achavalite and schmiederite.
His father was Austrian and his mother German. He studied geology at the National University of Córdoba (1930). He did an internship in Dresden (Germany) and for four years he was assistant to Professor Robert Beder in the chair of mineralogy at the University of Cordoba, a chair that Olsacher held for 30 years (1934-1964). He was also director of the Museum of Mineralogy and Geology of the university, director of the Provincial Museum of Natural Sciences of Cordoba and founder and editor of the journal Comunicaciones. He authored "Los minerales de la provincia de Córdoba" ("The minerals of the province of Córdoba") (1938) and "Los yacimientos minerales de la Sierra de Córdoba" ("The mineral deposits of the Sierra de Córdoba") (1942). In 1946, he published a celebrated textbook, "Introducción a la Cristalografía" ("Introduction to Crystallography").
His father was Austrian and his mother German. He studied geology at the National University of Córdoba (1930). He did an internship in Dresden (Germany) and for four years he was assistant to Professor Robert Beder in the chair of mineralogy at the University of Cordoba, a chair that Olsacher held for 30 years (1934-1964). He was also director of the Museum of Mineralogy and Geology of the university, director of the Provincial Museum of Natural Sciences of Cordoba and founder and editor of the journal Comunicaciones. He authored "Los minerales de la provincia de Córdoba" ("The minerals of the province of Córdoba") (1938) and "Los yacimientos minerales de la Sierra de Córdoba" ("The mineral deposits of the Sierra de Córdoba") (1942). In 1946, he published a celebrated textbook, "Introducción a la Cristalografía" ("Introduction to Crystallography").
An alteration product of penroseite and especially clausthalite.
Closely related to molybdomenite and paramolybdomenite.
Closely related to molybdomenite and paramolybdomenite.
Unique Identifiers
Mindat ID:
2987
Long-form identifier:
mindat:1:1:2987:8
IMA Classification of Olsacherite
Approved
IMA Formula:
Pb2+2(Se6+O4)(S6+O4)
Approval year:
1969
First published:
1969
Classification of Olsacherite
7.AD.35
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
A : Sulfates (selenates, etc.) without additional anions, without H2O
D : With only large cations
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
A : Sulfates (selenates, etc.) without additional anions, without H2O
D : With only large cations
32.1.3.1
32 : COMPOUND SULFATES
1 : Anhydrous Compound Sulfates
32 : COMPOUND SULFATES
1 : Anhydrous Compound Sulfates
28.2.1
28 : Selenites, Selenates, Tellurites, and Tellurates
2 : Selenates
28 : Selenites, Selenates, Tellurites, and Tellurates
2 : Selenates
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Ols | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Olsacherite
Vitreous, Dull
Transparency:
Transparent, Translucent
Comment:
dull if coated.
Colour:
Colorless
Streak:
White
Hardness:
3 - 3½ on Mohs scale
Tenacity:
Very brittle
Cleavage:
Distinct/Good
{101} good, {010} fair
{101} good, {010} fair
Density:
6.55 g/cm3 (Calculated)
Optical Data of Olsacherite
Type:
Biaxial (-)
RI values:
nα = 1.935(2) nβ = 1.966(2) nγ = 1.983(2)
2V:
Measured: 80° , Calculated: 84°
Max. Birefringence:
δ = 0.048
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
relatively weak
Chemistry of Olsacherite
Mindat Formula:
Pb2(Se6+O4)(SO4)
Element Weights:
Elements listed:
Crystallography of Olsacherite
Crystal System:
Orthorhombic
Cell Parameters:
a = 8.42(1) Å, b = 10.96(1) Å, c = 7.00(1) Å
Ratio:
a:b:c = 0.768 : 1 : 0.639
Unit Cell V:
645.98 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Elongated on [010]
Comment:
Point Group: 222 or mm2; Space Group: P2212, P222, or Pmm2.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.338 Å | (100) |
| 3.234 Å | (100) |
| 3.015 Å | (100) |
| 2.086 Å | (70) |
| 2.786 Å | (60) |
| 3.845 Å | (50) |
| 4.316 Å | (40) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 45a : [Sulfates, arsenates, selenates, antimonates] | |
| 47b : [Sulfates and sulfites] | |
| 47d : [Arsenates, antimonates, selenates, bismuthinates] | |
| 47h : [Near-surface oxidized, dehydrated minerals] |
Type Occurrence of Olsacherite
General Appearance of Type Material:
Occurs sparingly in well formed crystals coating the walls of small cracks or cavities.
Place of Conservation of Type Material:
Harvard University, Cambridge, Massachusetts, USA, 110966.
Geological Setting of Type Material:
Selenium deposit
Associated Minerals at Type Locality:
Synonyms of Olsacherite
Other Language Names for Olsacherite
Dutch:Olsacheriet
French:Acide selenieux
German:Olsacherit
Selenolit
Selenolit
Spanish:Olsacherita
Selenolita
Selenolita
Traditional Chinese:硒鉛礬
Common Associates
Associations Based on Photo Data:
| 12 photos of Olsacherite associated with Chalcomenite | CuSeO3 · 2H2O |
| 8 photos of Olsacherite associated with Molybdomenite | PbSeO3 |
| 6 photos of Olsacherite associated with Goethite | Fe3+O(OH) |
| 6 photos of Olsacherite associated with Tyrrellite | Cu(Co,Ni)2Se4 |
| 6 photos of Olsacherite associated with Umangite | Cu3Se2 |
| 6 photos of Olsacherite associated with Native Selenium | Se |
| 6 photos of Olsacherite associated with Kruťaite | CuSe2 |
| 5 photos of Olsacherite associated with Clausthalite | PbSe |
| 4 photos of Olsacherite associated with Klockmannite | CuSe |
| 4 photos of Olsacherite associated with Petříčekite | CuSe2 |
Related Minerals - Strunz-mindat Grouping
| 7.AD. | Bubnovaite | K2Na8Ca(SO4)6 |
| 7.AD. | Dobrovolskyite | Na4Ca(SO4)3 |
| 7.AD. | Calciolangbeinite | K2Ca2(SO4)3 |
| 7.AD. | Murphyite | Pb(Te6+O4) |
| 7.AD. | Cuprodobrovolskyite | Na4Cu(SO4)3 |
| 7.AD. | Kristjánite | KNa2H(SO4)2 |
| 7.AD.05 | Mascagnite | (NH4)2SO4 |
| 7.AD.05 | Arcanite | K2SO4 |
| 7.AD.10 | Mercallite | KHSO4 |
| 7.AD.15 | Misenite | K8H6(SO4)7 |
| 7.AD.20 | Letovicite | (NH4)3H(SO4)2 |
| 7.AD.25 | Thénardite | Na2SO4 |
| 7.AD.25 | Glauberite | Na2Ca(SO4)2 |
| 7.AD.30 | Metathénardite | Na2SO4 |
| 7.AD.30 | Anhydrite | CaSO4 |
| 7.AD.35 | Baryte | BaSO4 |
| 7.AD.35 | Celestine | SrSO4 |
| 7.AD.35 | Anglesite | PbSO4 |
| 7.AD.40 | Kalistrontite | K2Sr(SO4)2 |
| 7.AD.40 | Palmierite | K2Pb(SO4)2 |
| 7.AD.45 | Ivsite | Na3H(SO4)2 |
| 7.AD.55 | Markhininite | TlBi(SO4)2 |
Other Information
Electrical:
Pyroelectric
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Olsacherite
mindat.org URL:
https://www.mindat.org/min-2987.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Olsacherite
Reference List:
Bertrand, Emile (1882) Sur la molybdoménite (sélénite de plomb), la cobaltoménite (sélénite de cobalt) et l'acide sélénieux de Cacheuta (La Plata) Bulletin de Minéralogie, 5 (4) 90-92 doi:10.3406/bulmi.1882.1713
Localities for Olsacherite
Showing 17 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Argentina | |
|
Liauzun, Olloix, Clermont-Ferrand, Puy-de-Dôme, Auvergne-Rhône-Alpes, France