TY - JOUR
T1 - Colours of Gemmy Phosphates from the Gavà Neolithic Mines (Catalonia, Spain) :
T2 - Origin and Archaeological Significance
AU - Casas Duocastella, Lluís
AU - Díaz-Acha, Yael
AU - Campeny, Marc
AU - Ibañez-Insa, Jordi
AU - Jawhari, Tariq
AU - Bosch, Josep
AU - Borrell Tena, Ferran
AU - Jorge-Villar, Susana Esther
AU - Greneche, Jean-Marc
AU - Tauler, E.
AU - Melgarejo Draper, Joan Carles
PY - 2022
Y1 - 2022
N2 - 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, andFe Mössbauer spectrometry. Mapping of the mines indicates that colour is not directly dependent on depth. Although variscite from Gavà is poor in Cr and V compared with gemmy variscite from other localities, the deep green samples content has the highest values of Cr. 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.
AB - 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, andFe Mössbauer spectrometry. Mapping of the mines indicates that colour is not directly dependent on depth. Although variscite from Gavà is poor in Cr and V compared with gemmy variscite from other localities, the deep green samples content has the highest values of Cr. 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.
U2 - 10.3390/min12030368
DO - 10.3390/min12030368
M3 - Article
SN - 2075-163X
VL - 12
JO - Minerals
JF - Minerals
IS - 3
ER -