Chromium gives rubies a cool optical quirk. Most gemstones get their colour purely through absorption. They absorb certain wavelengths of white light and bounce the rest back to your eye. But Chromium does something extra: it is highly fluorescent. When invisible UV rays hit a fine Ruby, the Chromium atoms actually get excited and physically emit their own red light. If you take a high-quality Ruby out into direct sunlight, it’s literally glowing a little bit. This is why ancient texts constantl