• Black Star Sapphire Surprise

    Black Star Sapphire Surprise

    A large black star sapphire was brought in for testing. Two large pits on the base were carefully filled with brown dopping varnish. After removal of the varnish with alcohol, it was found that a large portion of the base had been filled with a lead glass.

  • Ruby Connoisseurship | Seeing Red

    Seeing Red  |  A Guide to Ruby Connoisseurship

    A loving look at ruby – the gem of passion – from the standpoint of the connoisseur.

  • Rutile in Corundum | Following the Silk Road

    Following the Silk Road  |  Rutile in Corundum

    A discussion of rutile silk in corundum and its use in detecting artificial heat treatment. Careful examination of these "silk" inclusions can provide vital clues to unmask heated gems.