Plata Kongsbergita
Plata is a mineral with formula Ag(Hg), in the Elementos Nativos group. This specimen comes from Corta San Matilde, Herrerías, Almería, Andalucía, España and joined the Terrium collection in 2006.
Description
Very fresh silver ball, without dark sulphide coating, with very fine, almost frosted dendritic growth, forming an aggregate with real volume—not poor wires or fragments—and a clear "nest" form. Extremely delicate.
History of this specimen
One of two smaller kongsbergite specimens—sisters to the large piece from the same find, which is now housed at the School of Mines. Their finder, Juan, discovered them at the Corta Santa Matilde open pit back when the machinery was still actively working the site, using his weekends to explore on his own. He would climb down to the bottom, cross unstable ground, and brace his back against the walls to keep from falling while reaching his arm into gaps and cavities up to his shoulder. In one of those voids, he felt the large 'bird's nest' that yielded these pieces. Because it was a Sunday afternoon, he had to extract it right then and there; by the next day, he would be back at school and the heavy machinery could easily raze the area. Juan also recalled that these mineralizations occurred at the contact between the barite and the silver amalgams, within marly ground rich in marine fossils
About Plata
The silver from Corta San Matilde is notable for dendritic and arborescent growths, commonly associated with mercury. These forms develop in cavities within marly materials, produced by low-temperature hydrothermal solutions.
About the locality
Corta San Matilde (Las Herrerías, Almería) is a modern open-pit operation developed over a historical mining district. The geological setting preserves the footprint of an ancient, compacted seafloor, clearly visible within the area's fossiliferous marls. A paleo-submarine hydrothermal system was channeled along faults, leading to subsequent mineralization inside cavities associated with barite. The final mining phase in the area (Grupo Berja) was conducted by MINERSA in 2006, targeting barite extraction for the cement, insulation, and specialized industrial sectors
Technical data
- Catalogue No.
- 0370
- Composition
- Ag(Hg)
- Name
- Plata
- Variety
- Kongsbergita
- Group
- Elementos Nativos
- Category
- Cupidium
- Mine
- Corta San Matilde
- District / Municipality
- Herrerías
- Province
- Almería
- Region
- Andalucía
- Country
- España
- Size (cm)
- 3.7 x 3.7 x 3.7
- Weight
- 23.5 g
- Acquired
- 2006
- Ex-collection
- Juan Morillas López
- Etymology
- From the element uranium and the Greek "kirkos" ("falcon"), in honour of the type locality Falkenstein ("Falcon Stone") in Bavaria, Germany.
- Quality
- Top
- Value trend
- Al alza
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