Alcantarillaite is a mineral, calcium arsenate, iron and wolfram, which has been described as a species from specimens found in the Alcantarilla mine, Belalcázar, province of Córdoba (Spain). Given the complexity and peculiarities of its chemical composition, it could not initially be identified, although it was provisionally considered as phyllotungstite, making it clear that it was probably a new species.[1] It was later described as a new species, which was accepted by the International Association of Mineralogy. [2] The name of the mineral derives from that of the mine where it was found.[3]
| Alcantarillaite | |
|---|---|
 Alcantarillaite. Section of a spherule showing laminar crystals, on quartz. Alcantarilla Mine, Belalcázar (Córdoba) Spain. Width, 1.5 mm | |
| General | |
| Category | Arsenate mineral |
| Formula (repeating unit) | [Fe3+0.5(H2O)4][CaAs3+2(Fe3+2.5W6+0.5)(AsO4)2O7] |
| Crystal system | Orthorhombic crystal system |
| Identification | |
| Color | bright yellow |
| Crystal habit | Clusters of lamellar microcrystals |
| Cleavage | Perfect - {100} |
| Fracture | Brittle |
| Luster | vitreous |
| Streak | Yellow |
| Density | 3.06 |
| Optical properties | Translucent |
| Refractive index | nα = 1,703 nβ = 1,800(5) nγ = 1,850(5) |
Properties edit
Although alcantarillaite is structurally related to walentaite, it represents a hitherto unique combination of elements. It is deep canary yellow in colour, and forms tabular or lamellar crystals up to a quarter of a millimetre in size, grouped divergently.
Deposits edit
Alcantarillaite is a secondary mineral, formed by the alteration of arsenides (probably loellingite) in the presence of tungsten minerals. It was approved as a species by the IMA in 2019 and formally published in 2020 The only known locality so far is the type locality, the Alcantarilla mine (or Nuestra señora de las Alcantarillas), in Belalcázar, province of Córdoba (Spain).[1] It occurs in fissures and cavities of a quartz vein associated with arsenopyrite, parasimplesite, karibibite and occasionally ferberite.
References edit
- ^ Rewitzer, C., Hochleitner, R., Fehr, T. y Utrera, C. (2016). "Karibibita, schneiderhöhnita, tooeleita y otros minerales secundarios poco comunes en la mina Nuestra Señora de las Alcantarillas, Belalcázar, Córdoba, España". Revista de Minerales. 6 (3): 8–39.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Hochleitner, R., Rewitzer, C., Grey, I.E., Riboldi-Tunnicliffe, A., Kampf, A.R., MacRae, C.M.,Mumme, W.G., Kaliwoda, M., Friis, H. y Utrera Martin, C. (2019). "Alcantarillaite, IMA 2019-072". CNMNC Newsletter No. 52. Mineralogical Magazine. 83.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Grey, I.E., Hochleitner, R., Rewitzer, C., Riboldi-Tunnicliffe, A., Kampf, A.R., MacRae, C.M., Mumme, W.G., Kaliwoda, M., Friis, H. y Utrera Martin, C. (2020). "The walentaite group and the description of a new member, alcantarillaite, from the Alcantarilla mine, Belalcázar, Córdoba, Andalusia, Spain". Mineralogical Magazine. 84 (3): 412–419. Bibcode:2020MinM...84..412G. doi:10.1180/mgm.2020.18. hdl:10852/78163. S2CID 216255272.
{{cite journal}}: CS1 maint: multiple names: authors list (link)