Prilep rubies are a variety of corundum found in the dolomitic marbles of the Prilep region in North Macedonia. This occurrence is scientifically notable for its specific mineralogical paragenesis including corundum, diaspore, and margarite.Barić, Lj. (1969). Dolomitmarmor in der Umgebung der Stadt Prilep und die in ihm vorkommenden Minerale.
Mineralogy and Optical Effects The corundum from Prilep frequently contains tiny oriented inclusions of diaspore (AlO(OH)). These inclusions result from structural epitaxy between the sapphire/ruby matrix and the diaspore lamellae.
Certain specimens exhibit a distinct internal shimmering effect, often silvery or whitish, known as diasporescence.Jeršek, M. (2015). Diasporescence in rubies from Prilep dolomitic marble. This optical phenomenon is caused by light reflecting off the microscopic planes of the oriented diaspore inclusions.
Scientific Importance The presence of diaspore inclusions serves as a key diagnostic feature for identifying the geographic origin of these gemstones. This specific type of intergrowth is characteristic of this deposit and is rarely observed with such intensity elsewhere.Jeršek et al. (2021). Diasporescence in rubies from Prilep.
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