Goethita Acicular-Laminar
Goethita is a mineral with formula FeO(OH), in the Óxidos group. This specimen comes from La Lastrilla, Tordelrábano, Guadalajara, Castilla-La Mancha, España and joined the Terrium collection in 1989.
Description
Lustrous black crystals with a fine prismatic habit lining a cavity. In places, the growths form extremely thin banded "ribbon" or "lamina" structures, nearly translucent in strong light.
About Goethita
Goethite (FeO(OH)) is an iron oxyhydroxide that typically forms in oxidised, low-temperature environments by alteration of iron-bearing minerals and in iron-rich sediments. At this occurrence it is found in carbonate nodules and in quartz or calcite geodes. The described acicular–laminar, ultrathin banded habit is very uncommon in Spanish goethites. These are goethite crystals in a calcite geode within the red sandstones of the Buntsandstein.
About the locality
The Tordelrábano outcrop (Guadalajara), discovered in the 1980s, yielded noted acicular goethite drapes in Iberian mineralogy. These geodes formed in carbonate nodules of the Lower Triassic—goethite crystals in calcite geodes within the red sandstones of the Buntsandstein. Constant traffic of collectors and visitors eventually disturbed local residents, who fenced off the area.
Technical data
- Catalogue No.
- 0360
- Composition
- FeO(OH)
- Name
- Goethita
- Variety
- Acicular-Laminar
- Group
- Óxidos
- Category
- Cavella
- Matrix
- Cuarzo, Calcita
- Mine
- La Lastrilla
- District / Municipality
- Tordelrábano
- Province
- Guadalajara
- Region
- Castilla-La Mancha
- Country
- España
- Size (cm)
- 3 x 3
- Acquired
- 1989
- Ex-collection
- Ángel García
- Etymology
- Named after the German Johann Wolfgang von Goethe, in recognition of his interest in mineralogy.
- Quality
- Notable
- Value trend
- Al alza
Related specimens
- Abellaíta — España
- Abernathyita — España
- Abernathyita — España
- Abernathyita — España
- Aerenita — España
- Aerinita (fibrosa) — España
- Analcima — España
- Analcima — España