CORUNDUM VAR. RUBY

ABOUT THE SPECIMEN Hot pink ruby crystals densely clustered together, showing a number of clearly defined faces and edges. Sivec is an ancient locality and one of the most famous deposits of corundum in Europe, and this is a really cute miniature that's also nicely representative! Fantastic bright red UV fluorescence.   VIDEO   MORE INFO The Sivec quarries exploit white dolomitic marble from the Pelagonian Massif, part of a 1,500-meter-thick metamorphic sequence dated 800-1,000 Ma that underwent regional metamorphism. The marble represents one of the purest dolomite marbles known, quarried since approximately 500 BCE and at peak production during Roman times when it was prized as sculptural stone. Ruby crystals form as tabular hexagonal forms within calcite veins, typically colored pink to purplish-red with occasional color-zoned examples. Specimens range from translucent to opaque with sizes reaching 3-4 cm, often showing characteristic silvery diaspore inclusions oriented in three 60-degree directions. What makes Sivec historically significant is its antiquity; these quarries produced gem corundum used in ancient jewelry and are among Europe's oldest continuously exploited mineral localities. Recent pockets discovered during modern marble exploitation have yielded large, well-formed crystals that rival older museum examples. The ruby forms through aluminum concentration during high-grade metamorphism of aluminous protoliths within the carbonate sequence. With modern dimension stone operations focused on marble rather than specimen recovery, collector-quality Sivec rubies remain scarce.