Practically no one knows how a ruby gemstone is treated to make it look more beautiful. In recent weeks there has been news of lead glass-filled rubies that are attracting gemstone lovers. Ruby is composed of Corundum, which is the crystalline form of aluminum oxide. After Diamonds, Ruby is the hardest gemstone. Natural rubies have been mined for 8,000 years or more. https://bluesapphireorgin.blogspot.com/2023/02/lead-glass-filled-ruby-gems-value-of.html