verneuil

  • Hidden Treasure — Collecting Books on Ruby & Sapphire

    Ruby & Sapphire Books • Collecting the Literature of Ruby & Sapphire (Corundum) • Hidden Treasure

    A discussion of the literature of ruby and sapphire (corundum), with particular emphasis on the most collectible books covering ruby and sapphire around the world.

  • Padparadscha or Pretender — An Unusual Pink-Orange Sapphire

    Padparadscha or Pretender • An Unusual Pink-Orange Sapphire

    An orangish pink “padparadscha” sapphire was submitted for testing at Lotus Gemology’s Bangkok laboratory. Testing showed a number of conflicting features that suggested the gem was a cleverly treated synthetic pink sapphire designed to imitate natural padparadscha.

  • Verneuil Synthetic Corundum ID — Dangerous Curves

    Dangerous Curves • A Reexamination of Verneuil Synthetic Corundum

    Virtually all gemologists are aware of the curved growth lines and gas bubbles in Verneuil (flame-fusion) synthetic corundum, but few understand exactly why they occur and how they are distributed in these stones. This article clarifies these important identifying features.