The

silver Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...

antimonide mineral An antimonide mineral is a mineral that contains antimonide for its main anion. The antimonides are structurally similar to the sulfides and are grouped with them in both the Dana and Strunz mineral classification systems. Examples include: * Bre ...

dyscrasite has the chemical formula Ag₃Sb. It is an opaque, silver white, metallic mineral which crystallizes in the orthorhombic

crystal system In crystallography, a crystal system is a set of point groups (a group of geometric symmetries with at least one fixed point). A lattice system is a set of Bravais lattices. Space groups are classified into crystal systems according to their po ...

. It forms pyramidal crystals up to and can also form cylindrical and prismatic crystals.Anthony, J.W., Bideau, R.A., Bladh, K.W., and Nichols, M.C. (1990) Handbook of Mineralogy: Volume I: Elements, Sulfides, Sulfosalts. 588 p. Mineral Data Publishing, Tucson, Arizona. http://rruff.geo.arizona.edu/doclib/hom/dyscrasite.pdf

Crystallography and properties

Dyscrasite is a metal ore and is opaque. In reflected light, however, it demonstrates weak anisotropism. Dyscrasite’s color under plane polarized light is most likely dark grey/black. When spun on a rotatable stage of a microscope (under plane polarized light), dyscrasite’s color should slightly change shades. This property is called

pleochroism Pleochroism (from Greek πλέων, ''pléōn'', "more" and χρῶμα, ''khrôma'', "color") is an optical phenomenon in which a substance has different colors when observed at different angles, especially with polarized light. Backgrou ...

. Dyscrasite exhibits very weak reflected light pleochroism. Dyscrasite belongs to the orthorhombic crystal class, meaning all three of its axes (a, b, and c) are unequal in length and are 90° to each other.Klein, C., and Dutrow, B. (2007) The Manual of Mineral Science, 23rd ed. 675 p. John Wiley & Sons, Inc. Hoboken, New Jersey.

Discovery and occurrence

It was first described for an occurrence in 1797 in the Wenzel Mine,

Black Forest The Black Forest (german: Schwarzwald ) is a large forested mountain range in the state of Baden-Württemberg in southwest Germany, bounded by the Rhine Valley to the west and south and close to the borders with France and Switzerland. It is t ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

. The name dyscrasite comes from the Greek word δυσκράσις, meaning "a bad alloy." It occurs as a

hydrothermal Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with th ...

mineral in silver bearing

veins Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...

in association with native silver,

pyrargyrite Pyrargyrite is a sulfosalt mineral consisting of silver sulfantimonite, Ag3SbS3. Known also as dark red silver ore or ruby silver, it is an important source of the metal. It is closely allied to, and isomorphous with, the corresponding sulfarse ...

acanthite 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 . Argentite is the stable form above that temperature. As argentite cools below that tem ...

, stromeyerite,

tetrahedrite Tetrahedrite is a copper antimony sulfosalt mineral with formula: . It is the antimony endmember of the continuous solid solution series with arsenic-bearing tennantite. Pure endmembers of the series are seldom if ever seen in nature. Of the two, ...

, allemontite,

galena Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver. Galena is one of the most abundant and widely distributed sulfide minerals. It cryst ...

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

and baryte.

References

{{Commons category Antimonide minerals Silver minerals Orthorhombic minerals Minerals in space group 25

Crystallography and properties

Discovery and occurrence

See also

References