Many parts of northeastern Greece contain deposits of diamonds, rubies and beryls that have remained untapped due to a lack of private investment and sufficient interest in gem-mining, geologists told a conference in Thessaloniki yesterday. «Rubies have been located 15 kilometers north of the town of Xanthi, in Thrace, where tiny emeralds no bigger than two millimeters are known to exist,» Vassilis Melfos of Thessaloniki University told the conference on «Geology and Society» that was organized by the Institute for Geological and Mining Studies (IGME). «But the lack of interest from private firms, the remote locations of most deposits and the fact that little research has hitherto been carried out into locating and assessing gem deposits have not permitted their exploitation so far.» Melfos presented a map of gem-bearing areas in northern Greece. Red corundum of ruby quality has also been spotted in the vicinity of Paranestio, in the Drama area, where crystals reach ten centimeters in length. And Kato Nevrokopi – best known as the coldest part of Greece – in the Drama area has yielded specimens of high-quality, deep purple amethyst among crystals of smoky quartz. Lower quality, large amethysts also exist in Sapes and Soufli in Thrace, while rhodochrosite, rhodonite and beautiful formations of calcite abound in the Stratoni and Olympias mines in Halkidiki. Achate, chalcedony and opal exist in the Evros area. Geologist Dimitrios Costopoulos said diamond-bearing rocks have been located in parts of northern Greece. He stressed that the gems known so far are very small in size. Extensive research will determine if deposits can be commercially exploited.