Furcalita
Furcalita is a mineral with formula Ca₂(UO₂)₃O₂(PO₄)₂·7H₂O, in the Fosfatos (Uranilo) group. This specimen comes from Mina Sítio do Castelo, Folgosinho, Gouveia, Guarda, Portugal and joined the Terrium collection in 2007.
Description
Very good specimen with a dense, crystallised crust of phurcalite on quartz matrix. Platy autunite crystals and areas of black botryoidal goethite provide contrast. Strongly fluorescent under UV. WARNING: highly active; 9,500 cpm on a Geiger counter.
History of this specimen
When Francisco Becerra was about thirteen or fourteen, his father used to take him to the premises of the Asociación Mineralógica Sevillana. He spent much time there with Lola Rosado, then Professor of Geology at the University of Seville and in charge of the place. One day Fran arrived with ten or fifteen 4×4 mineral boxes—those that hold fifty-four little pieces—to show her. As soon as she saw them, Lola put her hand on the boxes and stopped him short: "Look, this makes no sense, this way of spending money. All this is junk. Stop collecting crap, Paquito; buy pieces that have value." It hurt his pride, but he says the jolt woke him up. He understood her: a single extraordinary piece was worth more than a hundred mediocre ones. Although Lola had to insist a bit more, that lesson changed his life: his pastime became a professional vocation. Today he repeats that same philosophy to every client. He did with me. At first I did not understand him. Then it was clear to me.
About Furcalita
Scientific rarity. Phurcalite (also furcalite) carries its composition in the name: URanium and CALcium phosphate. Although its type locality is in Germany, Portugal has produced some of the best specimens worldwide.
About the locality
Sítio do Castelo mine (Folgosinho area) is the "Mecca" of uranium phosphates in the Iberian Peninsula. Originally a tungsten and tin operation, it became world-famous among collectors for the remarkable secondary mineralogy found in its oxidised fractures. A classic deposit that still yields surprises today, but specimens of this size, richness and purity (extracted in the 2007 heyday) are now very hard to find on the market.
Technical data
- Catalogue No.
- 0223
- Composition
- Ca₂(UO₂)₃O₂(PO₄)₂·7H₂O
- Name
- Furcalita
- Group
- Fosfatos (Uranilo)
- Category
- Núcleus Ardens
- Matrix
- Cuarzo
- Associations
- Autunita, Goethita
- Mine
- Mina Sítio do Castelo
- District / Municipality
- Folgosinho
- Province
- Gouveia
- Region
- Guarda
- Country
- Portugal
- Size (cm)
- 5.4 x 4 x 3.6
- Weight
- 67.4 g
- Acquired
- 2007
- Ex-collection
- Francisco Becerra
- Etymology
- Acronym from its chemical composition: PHosphate-URanium-CALcium.
- Quality
- Notable
- Value trend
- Al alza
Related specimens
- Autunita — Portugal
- Autunita — Portugal
- Autunita — Portugal
- Autunita (Verde) — Portugal
- Cuarzo — Portugal
- Descloizita — Portugal
- Descloizita — Portugal
- Dewindtita — Portugal