Discrasita
Discrasita is a mineral with formula Ag₃Sb. This specimen comes from Uranium Mine (Shaft 21), Háje / Dubno, Příbram District, Bohemia, República Checa and joined the Terrium collection in 1988.
Description
A 360° floater specimen of dyscrasite and silver pseudomorph after dyscrasite. It forms an open mass, almost like crystallized foam, full of cavities, torn edges and irregular ridges. On these ridges appear metallic spines, lamellae and ribbons of dyscrasite-silver; inside the cavities, filiform and dendritic growths show a golden metallic luster. A small fresh break reveals botryoidal metallic silver beneath the dark patina. A highly textured specimen, fragile in appearance, with excellent visual reading in hand and under magnification.
About Discrasita
Dyscrasite is the silver antimonide with the most clearly defined stoichiometry: three silver atoms for each antimony atom, Ag₃Sb. In this specimen, some of the crystals were originally dyscrasite, but secondary alteration processes, probably related to hydrothermal fluids, transformed them partly or completely into silver: externally they preserve the form of dyscrasite, while internally they are silver. Sometimes this transformation remains incomplete, and remnants of both minerals persist, as in this specimen. Stibarsen is the mineral previously known as Allemontite AsSb, a mixture of both arsenic and antimonium.
About the locality
The world's finest dyscrasite specimens came to light between 1980 and 1990 at Mine 21 of this Soviet uranium operation. Their chaotic, broken, and cavernous appearance resulted from hydrothermal fluids dissolving the original mineral and redepositing the silver into strange, whimsical shapes. This highly specific, now-closed location ultimately became the global benchmark for this stunningly beautiful mineral rarity.
Technical data
- Catalogue No.
- 0653
- Composition
- Ag₃Sb
- Name
- Discrasita
- Category
- Cupidium
- Matrix
- Plata
- Associations
- arsénico, estibarsénico
- Mine
- Uranium Mine (Shaft 21)
- District / Municipality
- Háje / Dubno
- Province
- Příbram District
- Region
- Bohemia
- Country
- República Checa
- Size (cm)
- 9 × 6 × 3.5
- Weight
- 103.8 g
- Acquired
- 1988
- Etymology
- Derived from the Greek word dyskrásis (δυσκράσις), meaning "bad alloy" or "bad mixture" (from dys- [bad/difficult] and krasis [mixture/combination])
- Quality
- Top
- Value trend
- Al alza
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