Novákite
A valid IMA mineral species
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About Novákite
Formula:
(Cu,Ag)21As10
Previously given as Cu20AgAs10.
Colour:
Steel-grey; Grey
Lustre:
Metallic
Hardness:
3 - 3½
Specific Gravity:
6.7
Crystal System:
Monoclinic
Name:
Named in honor of Dr. Jiří Novák (23 December 1902, Uherský Brod, Austria-Hungary - 21 May 1971), professor of mineralogy at Charles University, Prague. He later held positions of dean and vice-rector at the university.
This page provides mineralogical data about Novákite.
Unique Identifiers
Mindat ID:
2938
Long-form identifier:
mindat:1:1:2938:0
GUID
(UUID V4):
(UUID V4):
14822d7f-a81c-40cf-adf3-bb1cc7b39677
IMA Classification of Novákite
Approved
Approval year:
1960
First published:
1959
Type description reference:
Classification of Novákite
2.AA.15
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
A : Alloys
A : Alloys of metalloids with Cu, Ag, Au
2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
A : Alloys
A : Alloys of metalloids with Cu, Ag, Au
2.4.18.1
2 : SULFIDES
4 : AmBnXp, with (m+n):p = 2:1
2 : SULFIDES
4 : AmBnXp, with (m+n):p = 2:1
1.39
1 : Elements and Alloys (including the arsenides, antimonides and bismuthides of Cu, Ag and Au)
1 : Elements and Alloys (including the arsenides, antimonides and bismuthides of Cu, Ag and Au)
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 |
---|---|---|
Nvá | 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 Novákite
Metallic
Transparency:
Opaque
Colour:
Steel-grey; Grey
Comment:
Steel-grey on fresh surface, but turn iridescent and later black
Streak:
Black
Hardness:
3 - 3½ on Mohs scale
Cleavage:
None Observed
Density:
6.7 g/cm3 (Measured) 8.01 g/cm3 (Calculated)
Comment:
Value only approximate: intergrown with löllingite and chalcocite
Optical Data of Novákite
Anisotropism:
Medium strong: dark blue-gray and light brown ocher color effects in marginal positions
Reflectivity:
Wavelength | R1 | R2 |
---|---|---|
400nm | 43.6% | 49.0% |
420nm | 45.4% | 50.5% |
440nm | 47.2% | 52.0% |
460nm | 48.3% | 53.0% |
480nm | 49.1% | 53.9% |
500nm | 49.8% | 54.6% |
520nm | 50.2% | 55.2% |
540nm | 50.6% | 55.6% |
560nm | 50.9% | 56.0% |
580nm | 51.2% | 56.3% |
600nm | 51.3% | 56.6% |
620nm | 51.4% | 56.8% |
640nm | 51.5% | 56.9% |
660nm | 51.5% | 57.0% |
680nm | 51.5% | 57.1% |
700nm | 51.5% | 57.2% |
Graph shows reflectance levels at different wavelengths (in nm). Top of box is 100%. Peak reflectance is 57.2%.
R1 shown in black, R2 shown in red
Colour in reflected light:
White with pale cream tint
Pleochroism:
Non-pleochroic
Comments:
None observed.
Chemistry of Novákite
Mindat Formula:
(Cu,Ag)21As10
Previously given as Cu20AgAs10.
Previously given as Cu20AgAs10.
Elements listed:
Crystallography of Novákite
Crystal System:
Monoclinic
Cell Parameters:
a = 16.269(3) Å, b = 11.711(2) Å, c = 10.007(2) Å
β = 112.74°
β = 112.74°
Ratio:
a:b:c = 1.389 : 1 : 0.854
Unit Cell V:
1,758.39 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Granular aggregates
Comment:
Point Group: 2, m, or 2/m; Space Group: C2, Cm, or C2/m.
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
1.877 Å | (10) |
1.959 Å | (9) |
1.180 Å | (9) |
1.998 Å | (8) |
1.351 Å | (6) |
1.225 Å | (6) |
6.41 Å | (5) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
High-𝑇 alteration and/or metamorphism | |
33 : Minerals deposited by hydrothermal metal-rich fluids (see also [#12]) |
Type Occurrence of Novákite
General Appearance of Type Material:
Forms steel-gray granular aggregates.
Place of Conservation of Type Material:
National School of Mines, Paris, France; National Museum of Natural History, Washington, D.C., USA, 116992.
Geological Setting of Type Material:
Carbonate veins at Černý Důl, Czech Republic
Associated Minerals at Type Locality:
Reference:
Johan, Z., Hak, J. (1959) Novákit - (Cu,Ag)4As3, ein neues Mineral. Chemie der Erde: 20: 49-50.
Synonyms of Novákite
Other Language Names for Novákite
Common Associates
Associated Minerals Based on Photo Data:
Related Minerals - Strunz-mindat Grouping
2.AA. | Trigodomeykite | Cu3-xAs |
2.AA.10a | Algodonite | (Cu1-xAsx) |
2.AA.10b | Domeykite | Cu3As |
2.AA.10d | Koutekite | Cu5As2 |
2.AA.20 | Cuprostibite | Cu2(Sb,Tl) |
2.AA.25 | Kutinaite | Ag6Cu14As7 |
2.AA.30 | Allargentum | (Ag1-xSbx) |
2.AA.35 | Dyscrasite | Ag3Sb |
2.AA.40 | Maldonite | Au2Bi |
2.AA.45 | Stistaite | SnSb |
2.AA.50 | Zaccariniite | RhNiAs |
2.AA.55 | Dienerite | Ni3As |
Other Information
Notes:
Diagnostic etching: HNO3 1:1 positive; NCl I :1 positive; FeCl3 20 % positive; HgCl 5 % negative(film); KOH 40%negative; KCN 20% negative.
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 Novákite
mindat.org URL:
https://www.mindat.org/min-2938.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 Novákite
Reference List:
Johan, Z., Hak, J. (1961) Novákite, (Cu,Ag)4As3, a new mineral. American Mineralogist, 46 (7-8) 885-891
Johan, Z. (1985) The Černý Důl deposit (Czechoslovakia): An example of Ni-, Fe-, Ag-, Cu-arsenide mineralization with extremely high activity of arsenic; new data on paxite, novakite and kutinaite. TMPM Tschermaks Mineralogische und Petrographische Mitteilungen, 34 (3) 167-182 doi:10.1007/bf01082960
Localities for Novákite
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).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Czech Republic | |
| Černý |
| Chemie der Erde (1959) +3 other references |
Poland | |
| Kozłowski et al. (2022) |
USA | |
| Eckel et al. (1997) |
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Černý Důl, Trutnov District, Hradec Králové Region, Czech Republic