Acanthite

In today's article, we are going to delve into Acanthite, a relevant topic that has captured the attention of many people in recent times. Throughout this text, we will analyze different aspects of Acanthite, from its origins to its impact on today's society. We will immerse ourselves in its history, explore its implications in different areas and reflect on its importance in the current context. Acanthite is an exciting topic that deserves to be addressed from different perspectives, which is why in this article we aim to offer a broad and enriching vision of this matter. Join us on this fascinating exploration!

Acanthite
Crystallized acanthite (4.0 × 2.5 × 1.5 cm) from Imiter mine, Jbel Saghro mountain range, Morocco
General
CategorySulfide mineral
Formula
(repeating unit)		Ag2S
IMA symbolAca
Strunz classification2.BA.30a
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/n
Unit cella = 4.229 Å, b = 6.931 Å
c = 7.862 Å; β = 99.61°; Z = 4
Identification
ColorIron-black
Crystal habitPrimary crystals rare, prismatic to long prismatic, elongated along , may be tubular; massive. Commonly paramorphic after the cubic high-temperature phase ("argentite"), of original cubic or octahedral habit
TwinningPolysynthetic on {111}, may be very complex due to inversion; contact on {101}
CleavageIndistinct
FractureUneven
TenacitySectile
Mohs scale hardness2.0–2.5
LusterMetallic
StreakBlack
DiaphaneityOpaque
Specific gravity7.20–7.22
References

Acanthite is a form of silver sulfide with the chemical formula Ag2S. It crystallizes in the monoclinic system and is the stable form of silver sulfide below 173 °C (343 °F). Argentite is the stable form above that temperature. As argentite cools below that temperature its cubic form is distorted to the monoclinic form of acanthite. Below 173 °C acanthite forms directly. Acanthite is the only stable form in normal air temperature.

Occurrence

Acanthite is a common silver mineral in moderately low-temperature hydrothermal veins and in zones of supergene enrichment. It occurs in association with native silver, pyrargyrite, proustite, polybasite, stephanite, aguilarite, galena, chalcopyrite, sphalerite, calcite and quartz.

Acanthite was first described in 1855 for an occurrence in the Jáchymov (Joachimsthal) district, Ore Mountains, Bohemia (today Karlovy Vary Region, Czech Republic). The name is from the Greek "akantha" meaning thorn or arrow, in reference to its crystal shape.

Gallery

  • Acanthite. Locality: Chispas Mine, Arizpe, Sonora, Mexico. Scale is one inch with a ruled line at one cm.
    Acanthite. Locality: Chispas Mine, Arizpe, Sonora, Mexico. Scale is one inch with a ruled line at one cm.
  • Classic acanthite specimen from the Rayas Mine at Guanajuato, Mexico. Size: 2.4 × 1.1 × 1.1 cm.
    Classic acanthite specimen from the Rayas Mine at Guanajuato, Mexico. Size: 2.4 × 1.1 × 1.1 cm.

See also

References

Wikimedia Commons has media related to Acanthite.
Look up acanthite in Wiktionary, the free dictionary.
  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ Bonewitz, Ronald Louis (2012). Rocks and Minerals. Dorling Kindersley Limited. ISBN 978-0-7566-9042-7.
  3. ^ a b c Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (eds.). "Acanthite" (PDF). Handbook of Mineralogy. Chantilly, VA: Mineralogical Society of America.
  4. ^ a b Mindat.org
  5. ^ a b Webmineral data
  6. ^ a b c Klein, Cornelis and Cornelius S. Hurlbut, Manual of Mineralogy, Wiley, 20th ed., 1985, pp. 271-2 ISBN 0-471-80580-7
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