@article{3029745,
    title = "Spectroscopy and Microscopy of Corundum from Primary Deposits Found in
Greece",
    author = "Karantoni, Vilelmini and Karampelas, Stefanos and Voudouris, Panagiotis and and Melfos, Vasilios and Papadopoulou, Lambrini and Soldatos, and Triantafyllos and Mavrogonatos, Constantinos",
    journal = "Minerals",
    year = "2021",
    volume = "11",
    number = "7",
    publisher = "MDPI",
    issn = "2075-163X",
    doi = "10.3390/min11070750",
    keywords = "corundum; sapphire; Greece; FTIR; UV-Vis; EDXRF",
    abstract = "Corundum primary deposits in Greece occur in four locations: Paranesti
in Drama and Gorgona in Xanthi, both belonging to the wider Rhodope
Massif, as well as, Ikaria island and Kinidaros in Naxos island, both
belonging to Attic-Cycladic Massif. Eight samples were examined with
spectroscopic methods (FTIR, UV-Vis, EDXRF) in order to better
characterize these four primary deposits: two pink sapphires from
Paranesti, a pink and a blue sapphire from Gorgona, two blue sapphires
from Ikaria and three blue sapphires from Kinidaros. Under the
microscope, all samples present characteristics linked to
post-crystallization deformation, decreasing their gem quality. The FTIR
absorption spectra of all samples present in different relative
intensities, bands of boehmite, diaspore, goethite, mica and/or chlorite
inclusions and CO2 in fluid inclusions. Boehmite and diaspore inclusions
are most likely epigenetic. In the UV-Vis spectra, the pink color of the
samples is linked with Cr3+ absorptions and the blue color with
absorptions due to Fe2+-Ti4+ intervalence charge transfer. EDXRF
analyses in the studied samples show relatively high titanium and iron
concentrations that are related with mineral inclusions. Gallium is
slightly variable in samples from different regions; also, different
colored samples from Gorgona present diverse gallium content."
}