登录注册
Quick Links : Mindat手册The Rock H. Currier Digital LibraryMindat Newsletter [Free Download]
主页关于 MindatMindat手册Mindat的历史版权Who We Are联系我们于 Mindat.org刊登广告
捐赠给 MindatCorporate Sponsorship赞助板页已赞助的板页在 Mindat刊登 广告的广告商于 Mindat.org刊登广告
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsThe Rock H. Currier Digital LibraryGeologic Time
搜索矿物的性质搜索矿物的化学Advanced Locality Search随意显示任何一 种矿物Random Locality使用minID搜索邻近产地Search Articles搜索词汇表更多搜索选项
搜索:
矿物名称:
地区产地名称:
关键字:
 
Mindat手册添加新照片Rate Photos产区编辑报告Coordinate Completion Report添加词汇表项目
Mining Companies统计会员列表Mineral MuseumsClubs & Organizations矿物展及活动The Mindat目录表设备设置The Mineral Quiz
照片搜索Photo GalleriesSearch by Color今天最新的照片昨天最新的照片用户照片相集过去每日精选照片相集Photography

Acanthite

A valid IMA mineral species - grandfathered
This page kindly sponsored by Mark Kucera
Hide all sections | Show all sections

About AcanthiteHide

Formula:
Ag2S
Colour:
lead grey, black
Lustre:
Metallic
Hardness:
2 - 2½
Specific Gravity:
7.2 - 7.4
Crystal System:
Monoclinic
Member of:
Name:
Named in 1855 by Gustav Adolf Kenngott from the Greek άκανθα ("akantha") meaning "thorn", in allusion to the thorn-like crystal shape of his material. With the advent of instrumental analytical equipment, it was discovered that the mineral called "argentite" which had isometric crystal shapes has an atomic structure and chemistry identical to acanthite.
Dimorph of:
Isostructural with:
Acanthite is the low-temperature modification of silver sulphide.

All natural silver sulphide specimens at room temperatures are acanthite.
The structure of Argentite, the high-temperature cubic (isometric) form cannot be quenched. At atmospheric pressure, argentite is stable above 177°C and acanthite is stable below 177°C. Most acanthite crystals are paramorphs, which formed above the transition temperature and retain an isometric shape below the transition temperature, but have monoclinic symmetry at the atomic level.

The tarnish on manufactured sterling silver objects is chemically the same as acanthite.


Unique IdentifiersHide

Mindat ID:
10
Long-form identifier:
mindat:1:1:10:5
GUID
(UUID V4):
42460b0a-a0f4-4a29-8046-035a65bb60c0

IMA Classification of AcanthiteHide

Approved, 'Grandfathered' (first described prior to 1959)

Classification of AcanthiteHide

2.BA.35

2 : SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.)
B : Metal Sulfides, M: S > 1: 1 (mainly 2: 1)
A : With Cu, Ag, Au
Dana 7th ed.:
2.4.1.1
2.4.1.1

2 : SULFIDES
4 : AmBnXp, with (m+n):p = 2:1
3.2.1

3 : Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)
2 : Sulphides etc. of Ag

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference
AcaIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Pronunciation of AcanthiteHide

Pronunciation:
PlayRecorded byCountry
Jolyon RalphUnited Kingdom

Physical Properties of AcanthiteHide

Metallic
Transparency:
Opaque
Colour:
lead grey, black
Streak:
lead grey
Hardness:
2 - 2½ on Mohs scale
Hardness:
VHN50=21 - 25 kg/mm2 - Vickers
Hardness Data:
Measured
Tenacity:
Sectile
Cleavage:
None Observed
Fracture:
Sub-Conchoidal
Density:
7.2 - 7.4 g/cm3 (Measured)    7.24 g/cm3 (Calculated)

Optical Data of AcanthiteHide

Anisotropism:
Weak
Reflectivity:
WavelengthR
400nm32.8%
420nm32.9%
440nm33.0%
460nm33.1%
480nm33.0%
500nm32.7%
520nm32.0%
540nm31.2%
560nm30.5%
580nm29.9%
600nm29.2%
620nm28.7%
640nm28.2%
660nm27.6%
680nm27.0%
700nm26.4%

Reflectance graph
Graph shows reflectance levels at different wavelengths (in nm). Top of box is 100%. Peak reflectance is 33.1%.

Chemistry of AcanthiteHide

Mindat Formula:
Ag2S
CAS Registry number:
21548-73-2

CAS Registry numbers are published by the American Chemical Society
Common Impurities:
Se

Crystallography of AcanthiteHide

Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/m
Cell Parameters:
a = 4.229 Å, b = 6.931 Å, c = 7.862 Å
β = 99.61°
Ratio:
a:b:c = 0.61 : 1 : 1.134
Unit Cell V:
227.21 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Typically found as pseudo-cubic and pseudo-octahedral crystals, paramorphic after argentite. Also found as thorn-shaped monoclinic crystals, usually small to microscopic in size. Large primary crystals are uncommon, other than fine overgrowths and replacements of native silver; they are prismatic to long prismatic, elongated along [001], to 2.5 cm, may be tubular; also massive.

Crystallographic forms of AcanthiteHide

Crystal Atlas:
Image Loading
Click on an icon to view
Argentite no.11 - Goldschmidt (1913-1926)
Argentite - {100}, modified
3d models and HTML5 code kindly provided by www.smorf.nl.

Toggle
Edge Lines | Miller Indices | Axes

Transparency
Opaque | Translucent | Transparent

View
Along a-axis | Along b-axis | Along c-axis | Start rotation | Stop rotation

Crystal StructureHide

Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File    Best | x | y | z | a | b | c
Rotation
Stop | Start
Labels
Console Off | On | Grey | Yellow
IDSpeciesReferenceLinkYearLocalityPressure (GPa)Temp (K)
0010584AcanthiteFrueh A J (1958) The crystallography of silver sulfide, Ag2S Zeitschrift fur Kristallographie 110 136-1441958Freiberg, Saxony, Germany0293
CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
3.96 Å(10)
3.571 Å(6)
3.437 Å(35)
3.383 Å(20)
3.080 Å(60)
2.836 Å(70)
2.664 Å(45)
2.606 Å(100)
2.583 Å(70)
2.456 Å(70)
2.440 Å(80)
2.421 Å(60)
2.383 Å(80)
2.213 Å(45)
2.093 Å(16)
2.083 Å(45)
2.072 Å(16)
2.047 Å(16)
1.995 Å(16)
1.963 Å(20)
1.935 Å(4)
1.918 Å(4)
1.903 Å(14)
1.866 Å(16)
1.816 Å(4)
1.798 Å(4)
1.733 Å(12)
1.718 Å(20)
1.691 Å(6)
1.610 Å(4)
1.587 Å(14)
1.579 Å(10)
1.554 Å(8)
1.540 Å(8)
1.513 Å(12)
1.483 Å(10)
1.470 Å(10)
1.459 Å(14)
1.379 Å(6)
Comments:
ICDD 14-72

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
High-𝑇 alteration and/or metamorphism
33 : Minerals deposited by hydrothermal metal-rich fluids (see also [#12])
Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere<0.6
49 : Oxic cellular biomineralization (see also #44)<0.54
Geological Setting:
A common silver species in moderately low-temperature hydrothermal sulphide veins, and in zones of secondary enrichment.

Widespread in silver deposits. Localities for fine primary and paramorphic crystals include Jáchymov (St Joachimsthal), Czech Republic [TL]; In Germany, at Freiberg, Schneeberg, Annaberg, and Marienberg, Saxony; and from St Andreasberg, Harz. In Mexico, large paramorphs from Arizpe, Sonora; In the Rayas and other mines at Guanajuato; And from many mines in Zacatecas, Chihuahua, etc; In the USA, at Butte, Silver Bow Co., Montana; Tonopah, Nye Co. and the Comstock Lode, Virginia City, Storey Co., Nevada; From various mines at Cobalt, Ontario, Canada; At Chañarcillo, south of Copiapó, Atacama, Chile.

Type Occurrence of AcanthiteHide

Synonyms of AcanthiteHide

Other Language Names for AcanthiteHide

Varieties of AcanthiteHide

Zinc-bearing AcanthiteClearly needs reliable verification.

Relationship of Acanthite to other SpeciesHide

Member of:
Other Members of this group:
AguilariteAg4SeSMon. 2/m
CervelleiteAg4TeSMon. 2/m

Common AssociatesHide

Associated Minerals Based on Photo Data:
1,202 photos of Acanthite associated with SilverAg
371 photos of Acanthite associated with CalciteCaCO3
319 photos of Acanthite associated with QuartzSiO2
145 photos of Acanthite associated with PyriteFeS2
118 photos of Acanthite associated with Polybasite[Ag6Sb2S7][Ag9CuS4]
112 photos of Acanthite associated with ChalcopyriteCuFeS2
86 photos of Acanthite associated with ProustiteAg3AsS3
86 photos of Acanthite associated with GalenaPbS
77 photos of Acanthite associated with PyrargyriteAg3SbS3
66 photos of Acanthite associated with StephaniteAg5SbS4

Related Minerals - Strunz-mindat GroupingHide

2.BA.Orileyite(Fe,Cu)2As
2.BA.AlburniteAg8GeTe2S4Iso.
2.BA.DzierżanowskiteCaCu2S2Trig. 3m (3 2/m) : P3m1
2.BA.MakotoiteAg12(Cu3Au)S8Trig. 3m (3 2/m) : R3c
2.BA.XuwenyuaniteAg9Fe3+Te2S4Iso. 4 3m : F4 3m
2.BA.05ChalcociteCu2SMon. 2/m : P21/b
2.BA.05DjurleiteCu31S16Mon. 2/m
2.BA.05GeeriteCu8S5Trig. 3
2.BA.05RoxbyiteCu9S5Tric. 1 : P1
2.BA.10AniliteCu7S4Orth. mmm (2/m 2/m 2/m) : Pnma
2.BA.10DigeniteCu9S5Trig. 3m (3 2/m) : R3m
2.BA.15BorniteCu5FeS4Orth. mmm (2/m 2/m 2/m) : Pbca
2.BA.20BellidoiteCu2SeTet. 4/m : P42/n
2.BA.20BerzelianiteCu2-xSe (x ≈ 0.12)Iso. m3m (4/m 3 2/m) : Fm3m
2.BA.25AthabascaiteCu5Se4Orth.
2.BA.25UmangiteCu3Se2Tet. 4 2m : P4 21m
2.BA.30RickarditeCu7Te5Orth. mmm (2/m 2/m 2/m) : Pmmn
2.BA.30WeissiteCu2-xTeHex. 6/mmm (6/m 2/m 2/m) : P6/mmm
2.BA.35SpryiteAg8(As3+0.5As5+0.5)S6Orth. mm2 : Pna21
2.BA.40MckinstryiteAg5-xCu3+xS4Orth. mmm (2/m 2/m 2/m) : Pnma
2.BA.40StromeyeriteAgCuSOrth. mmm (2/m 2/m 2/m)
2.BA.40dUM2003-13-S:AgAuCuAg6AuCu2S5
2.BA.42HoneaiteAu3TlTe2 Orth. mmm (2/m 2/m 2/m) : Pbcm
2.BA.45JalpaiteAg3CuS2Tet. 4/mmm (4/m 2/m 2/m) : I41/amd
2.BA.45KuriliteAg8Te3SeTrig. 3 : R3
2.BA.45SelenojalpaiteAg3CuSe2Tet. 4/mmm (4/m 2/m 2/m) : I41/amd
2.BA.47Spiridonovite(Cu1-xAgx)2TeTrig. 3m (3 2/m) : P3c1
2.BA.50EucairiteAgCuSeOrth.
2.BA.50WuyanzhiiteCu2STet. 4 2 2 : P43 21 2
2.BA.52ArgentiteAg2SIso.
2.BA.55AguilariteAg4SeSMon. 2/m
2.BA.55NaumanniteAg2SeOrth. 2 2 2 : P21 21 21
2.BA.60CervelleiteAg4TeSMon. 2/m
2.BA.60HessiteAg2TeMon. 2/m : P21/b
2.BA.60ChenguodaiteAg9Fe3+Te2S4Orth.
2.BA.65Henryite(Cu,Ag)3+xTe2 , with x ~ 0.40 Iso. m3m (4/m 3 2/m) : Fd3c
2.BA.65StütziteAg5-xTe3, x = 0.24-0.36Hex. 6 : P6
2.BA.70ArgyroditeAg8GeS6Orth. mm2 : Pna21
2.BA.70CanfielditeAg8SnS6Orth. mm2
2.BA.70Putzite(Cu4.7Ag3.3)GeS6Iso. 4 3m : F4 3m
2.BA.75FischesseriteAg3AuSe2Iso. 4 3 2 : I41 3 2
2.BA.75Penzhinite(Ag,Cu)4Au(S,Se)4Hex. 6 2 2 : P63 2 2
2.BA.75PetrovskaiteAuAgSMon.
2.BA.75PetziteAg3AuTe2Iso. 4 3 2 : I41 3 2
2.BA.75UytenbogaardtiteAg3AuS2Trig. 3m (3 2/m) : R3c
2.BA.80Bezsmertnovite(Au,Ag)4Cu(Te,Pb)Orth.
2.BA.80BilibinskitePbCu2Au3Te2Iso.
2.BA.80Bogdanovite(Au,Te,Pb)3(Cu,Fe)Iso.

Fluorescence of AcanthiteHide

Not fluorescent in UV

Other InformationHide

Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Acanthite in petrologyHide

An essential component of rock names highlighted in red, an accessory component in rock names highlighted in green.

Internet Links for AcanthiteHide

References for AcanthiteHide

Reference List:

Localities for AcanthiteHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListShow

This section is currently hidden. Click the show button to view.
 
矿物 and/or 产地  
Mindat Discussions Facebook Logo Instagram Logo Discord Logo
版权所有© mindat.org1993年至2024年,除了规定的地方。 Mindat.org全赖于全球数千个以上成员和支持者们的参与。
隐私政策 - 条款和条款细则 - 联络我们 - Report a bug/vulnerability Current server date and time: 2024.3.19 03:15:05 Page updated: 2024.3.19 00:45:02
Go to top of page