It is believed that the alkaline complex became inсluded into the separate Sysertsk-Ilmenogorsk microcontinent with unconstrained borders, when sandwiched between Kazakhstania and Laurussia during that collision.

The mobile belt is a product of the collision among Kazakhstania, Laurussia, and Siberia continents prior to the closure of the Paleo-Uralian ocean and formation of the Laurasia supercontinent (330 – 250 Ma). An example is the Ilmenogorsky alkaline complex, within the Ilmen Mountains region and part of the Uralian orogenic belt. However, a systematic link of primary magmatic blue sapphire occurrences to orogenic belts is less understood. Metamorphic gem corundum (mainly ruby) deposits are robust indicators of continent-continent collision processes. Gallium is slightly variable in samples from different regions also, different colored samples from Gorgona present diverse gallium content. EDXRF analyses in the studied samples show relatively high titanium and iron concentrations that are related with mineral inclusions. In the UV-Vis spectra, the pink color of the samples is linked with Cr 3+ absorptions and the blue color with absorptions due to Fe 2+-Ti 4+ intervalence charge transfer. Boehmite and diaspore inclusions are most likely epigenetic. 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. Under the microscope, all samples present characteristics linked to post-crystallization deformation, decreasing their gem quality. 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. 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.

Corundum blue