The Fiery King
The word "Ruby" comes from the Latin ruber, meaning red. Throughout history, rubies have symbolized power, passion, and protection. Ancient warriors in Burma even believed that inserting a ruby into their flesh would make them invincible in battle.
The Chemistry of Red
Like sapphire, ruby is a form of Corundum. What makes it red is Chromium.
However, Chromium is a geological "party pooper." While it provides the red color, it also creates cracks and inclusions that make large, clean rubies extremely rare. This is why a top-quality 5-carat ruby can be significantly more expensive than a 5-carat diamond.
Fluorescence: The Inner Glow
One reason Mogok (Burmese) rubies are so prized is their low iron content. Iron suppresses fluorescence. When Burmese rubies are exposed to sunlight (which contain UV rays), the chromium in the stone glows red. This creates a "glow" effect where the stone appears to be burning from the inside—the legendary "Pigeon Blood" effect.
Lapidary Considerations
For a gem cutter, ruby is one of the most difficult materials to master. Because of its extreme hardness (Mohs 9) and the common presence of internal fractures, it requires specialized diamond abrasive wheels and careful temperature control during the polishing phase.
When you hold a truly fine ruby, you aren't just holding a rock; you are holding one of the rarest gifts of the geological world.