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.
Description
Lustrous black, slender prismatic crystals lining a cavity. In places the growths form extremely fine banded "ribbon" or "lamina" structures, almost translucent in strong light. Well suited to inspection with a loupe.
About Goethita
Forms as acicular "carpets" lining calcite geodes within carbonate nodules; quartz-lined geodes also occur. This acicular-laminar structure is very uncommon in Spanish goethite and is noted for its rarity and aesthetics.
About the locality
A classic Iberian locality for acicular goethite in geodes. Discovered in the 1980s, it yielded some of the finest and most aesthetic "carpets" in Spanish mineralogy. The geodes formed in carbonate nodules of the Lower Triassic within the red sandstones of the Buntsandstein. Repeated visits by collectors and the curious annoyed local residents, who eventually fenced off the area.
Technical data
- Catalogue No.
- 0309
- 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
- Etymology
- Named in honour of Johann Wolfgang von Goethe, writer and student of nature.
- Quality
- Buena
- Value trend
- Estable
Related specimens
- Abellaíta — España
- Abernathyita — España
- Abernathyita — España
- Abernathyita — España
- Aerenita — España
- Aerinita (fibrosa) — España
- Analcima — España
- Analcima — España