I have been trying to find videos that will help explain gemstone treatments to my readers, and how they may effect the pricing of the gem. This video by AGI is talking about glass filled rubies, or fissure filled as some places call them, and how the treatment takes place. It is very interesting. It is actually a three step process that starts with heating the rough, then chemical leaching, and finally filling the gems with glass or lead. Sometimes you get a percentage of quite a bit of ruby, and others not so much. I would think this would be impossible to tell when purchasing these gemstones. They are really remarkably beautiful, I however would not pay a great deal of money for these rubies.