Corundum is not uncommon on Earth but the gem varieties of ruby and sapphire are
relatively rare. Gem corundum deposits are classified as primary and secondary deposits …

Raman and photoluminescence (PL) map** is a non-destructive method which allows
gemologists and scientists to evaluate the spatial distributions of defects within a gem; it can …

Ruby in diverse geological settings leaves petrogenetic clues, in its zoning, inclusions, trace
elements and oxygen isotope values. Rock-hosted and isolated crystals are compared from …

Direct dating of corundum and the establishment of age constraints for corundum crystal
growth are restricted due to the absence of a geochronometer. Syngenetic mineral …

Rare ruby crystals appear among prevailing sapphire crystals mined from placers within
basaltic areas in the New England gem-field, New South Wales, Australia. New England …

The Snezhnoe ruby deposit is located in the Muzkol–Rangkul anticlinorium within the
Cimmerian zone of the Central Pamir. On the local scale, the deposit occurs on discrete …

The chemical composition and spectra of untreated and heat-treated rubies from
Mozambique and Madagascar were analyzed by an electron probe microscopy analysis …

Abstract Gem-quality (cabochon) ruby-bearing occurrences (here termed PAR-1 and PAR-5)
located near Paranesti, north eastern Greece have been systematically studied for the first …

Metamorphic gem corundum (mainly ruby) deposits are robust indicators of continent-
continent collision processes. However, a systematic link of primary magmatic blue sapphire …

Corundum is rarely found in situ within alkali syenites. A corundum-bearing syenite was
found in the Yushishan rare metal deposits of the eastern section of the Altyn Tagh fault in …