Colours of Gemmy Phosphates from the Gavà Neolithic Mines (Catalonia, Spain): Origin and Archaeological Significance

In the Neolithic Gavà mines, variscite and turquoise were exploited for ornaments manufacturing, although some prospective pits and tunnels were dug on other similar greenish minerals such as smectite or kandite. A 3D study of the distribution of mineral phases allows us to determine the parameters...

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Detalles Bibliográficos
Autores: Díaz-Acha, Yael, Campeny, Marc, Casas, Lluís, Di Febo, Roberta, Ibáñez Insa, Jordi, Jawhari, Tariq, Bosch, Josep, Borrell, Ferran, Jorge-Villar, Susana Esther, Grenèche, Jean Marc, Tauler, Esperança, Melgarejo, Joan Carles
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/266930
Acceso en línea:http://hdl.handle.net/10261/266930
https://api.elsevier.com/content/abstract/scopus_id/85126743560
Access Level:acceso abierto
Palabra clave:Turquoise
Variscite
Neolithic mines
Phosphates
Colour
Gavà
Descripción
Sumario:In the Neolithic Gavà mines, variscite and turquoise were exploited for ornaments manufacturing, although some prospective pits and tunnels were dug on other similar greenish minerals such as smectite or kandite. A 3D study of the distribution of mineral phases allows us to determine the parameters involved in variscite colours. Methods are comprised of quantitative colourimetry, thin section petrography, SEM-BSE-EDS, EMPA, XRD, Raman spectroscopy, and57Fe Mössbauer spectrometry. Mapping of the mines indicates that colour is not directly dependent on depth. Although variscite from Gavà is poor in Cr3+ and V+3 compared with gemmy variscite from other localities, the deep green samples content has the highest values of Cr3+. In the case of cryptocrystalline mixtures with jarosite, phosphosiderite, or goethite, variscite tends to acquire a greenish brown to olivaceous hue. If white minerals such as quartz, kandite, crandallite, or alunite are involved in the mixtures, variscite and turquoise colours become paler.