ALGT recently received strings of ruby beads purchased by a client at the Hong Kong Jewellery Fair.

ALGT recently received strings of ruby beads purchased by a client at the Hong Kong Jewellery Fair, which are vivid to deep red and quite transparent. His supplier told him that the strings are from Longido, Tanzania. The chemical analysis showed a high content of iron. Observing the inclusions with a darkfield microscope at 30-40 times magnification, these ruby beads have been heated, and there are borax residues in the fissures, which are common in heated rubies; I also noticed that some of the rubies have small flat bubbles in them, which means they have been treated by the FAPFH (flux‐assisted partial‐fissure‐healing) process. So the final conclusion is that these natural ruby strings have been heated with a minor to moderate amount of residue, in addition, a minor to moderate amount of glass filling used to reduce the visibility of the fissures and thus increase transparency. However, there is no lead glass filling.