Aragonito Pantojo
Aragonito is a mineral with formula CaCO₃, in the Carbonatos group. This specimen comes from Pantoja, Pantoja, Toledo, Castilla-La Mancha, España.
Description
Cream-coloured acicular crystals in a cavity of lacustrine matrix. Well-defined radial aggregate with vitreous lustre. The piece is notable for the perfection of the rosette and the cleanliness of the cavity.
History of this specimen
This piece has been with us for several years.
About Aragonito
One of the great underrated treasures of Iberian geology. Popularly known as "pantojos" or "hedgehog aragonites", these specimens stand out for their extreme delicacy and intense bluish-white fluorescence and phosphorescence. Aragonite is one of the most common crystalline forms of calcium carbonate; in Pantoja, its iconic acicular crystals developed inside cavities within ancient lake sediments.
About the locality
Pantoja became famous during the 1980s and 1990s for its acicular aragonite specimens, extracted from a quarry near the town that is now inactive and partially restored. The crystals occur inside small cavities within Miocene lacustrine sediments dating back around 14 million years. These clays were deposited in calm water zones and river mouths within inland freshwater lakes until they completely filled them. During sedimentation, decomposing organic matter generated gases that produced bubbles within the sediment. Later on, calcium carbonate-rich waters circulated through these cavities, precipitating into the characteristic radial aggregates. They were common in Spanish mineral fairs and among collectors in Castilla-La Mancha for decades. Today, specimens still turn up, though much less frequently.
Technical data
- Catalogue No.
- 0030
- Composition
- CaCO₃
- Name
- Aragonito
- Variety
- Pantojo
- Group
- Carbonatos
- Category
- Lucimera
- Matrix
- Caliza
- Mine
- Pantoja
- District / Municipality
- Pantoja
- Province
- Toledo
- Region
- Castilla-La Mancha
- Country
- España
- Size (cm)
- 5.5 x 4 x 3
- Weight
- 43.7 g
- Etymology
- The name "aragonite" comes from Molina de Aragón (Guadalajara, Spain), where it was first described in the 18th century. It refers directly to its geographical origin.
- Quality
- Muy buena
- Value trend
- Estable
Related specimens
- Aragonito (Blanco (Bulboso)) — España
- Barita — España
- Calcita —
- Calcita (Manganocalcita) — Pakistán
- Calcita (Dorada) — España
- Jacinto de Compostela — España
- Magnetita — España
- Magnetita — España