Goethita Botrioidal iridiscente
Goethita is a mineral with formula FeO(OH), in the Hidróxidos group. This specimen comes from Filón Sur, Minas de Tharsis, Alosno, Huelva, Andalucía, España and joined the Terrium collection in 2025.
Description
Elongate stalactitic structure with botryoidal habit, composed of concentric aggregates that traverse the piece as an irregular column. The surface bears an iridescent patina typical of Tharsis, with green, magenta, golden and bluish reflections that intensify under light. Vertical, slender natural growth with dense texture and branching forms resembling a fossilised metallic coral.
History of this specimen
Juanito El Tarta collected it half a century ago, and it then passed to Paquito el Malagueño, a keen collector of goethites, to which he attached a personal value even above his celebrated pyromorphites from Santa Eufemia—some of the best in the world—which he collected himself. He was the one who presented those pyromorphites as a new find at the Munich show, which made a strong impression. This goethite, by contrast, he kept with special regard before handing it to Diego Navarro, who kept it for 25 years, until it finally reached me as a living part of a field lineage. That find at Santa Eufemia was not accidental: earthworks caused several pieces to fall from the roof, as the mine was already exhausted.
About Goethita
Although goethite is a common iron oxyhydroxide in oxidising environments, at Tharsis it develops distinctive botryoidal and stalactitic morphologies, accompanied by stable iridescent patinas that clearly distinguish it from other localities.
About the locality
Tharsis forms part of the Iberian Pyrite Belt, a mining-metallogenic complex with more than 5000 years of history. The goethites from Filón Sur became well known for their iridescent patina, recognised since the reopening of the mine in 2007.
Technical data
- Catalogue No.
- 0096
- Composition
- FeO(OH)
- Name
- Goethita
- Variety
- Botrioidal iridiscente
- Group
- Hidróxidos
- Category
- Estélites
- Mine
- Filón Sur, Minas de Tharsis
- District / Municipality
- Alosno
- Province
- Huelva
- Region
- Andalucía
- Country
- España
- Size (cm)
- 12.5 x 4 x 2
- Weight
- 71 g
- Acquired
- 2025
- Ex-collection
- Diego Navarro
- Etymology
- Named for the German mineralogist 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