How Does the Sunlight Impact the Color of a Ruby?

Many rubies can shine when exposed to sunlight. Strong beliefs in many societies thought it was due to their magical powers. We would have loved this answer to be true but they actually glow because of ultraviolet rays. The sun's UV rays make the chromium shine within the gem. Certain rubies, particularly those found in marble (from places like Burma or Vietnam), exhibit a strong red fluorescence in daylight, intensifying the color of the stone and giving it the appearance of glowing red.

Let's have a look at what makes this particular aspect of the ruby so gorgeous.

To understand why we have to look into the internal composition of a ruby. When electrons are excited by a source of radiation, they jump to a higher degree of energy around the nucleus of the atom. The excited electron stays in this excited state for a brief period before it slips back to its initial state. When the electron returns to its ground state, it releases energy either as heat or as visible light.

With more than a decade of marketing experience, I am now based in Bangkok where I combine my professional background with a long-standing passion for gemstones. I write articles that explore both the beauty and the business of gems, offering insights into their history, trade, and market dynamics. My goal is to make the world of gemstones more accessible to anyone curious to learn, while bringing in the perspective of someone who understands both storytelling and strategy.