The Magic of Moonstone: What makes this gem glow
Moonstone has a quality that seems almost otherworldly - a luminous, ethereal glow that appears to come from deep within the stone itself. This enchanting phenomenon, known as adularescence or shiller, is what makes moonstone such a captivating gemstone.
Now, as a collector, I’ll admit it's a stone I never truly appreciated until recently, and now I want to share the fascinating science behind its beauty, a secret that also explains why the sky is blue. A two-for-one educational blog - how could you refuse?!
The Inner Glow: What Causes Adularescence?
When we look at opals, their famous play of colour is caused by light reflecting off microscopic, spherical particles within the stone, splitting into a rainbow of colours. Moonstone's unique effect is a more focused, almost magical version of this.
The adularescence you see in moonstone is not a surface reflection. It is caused by light hitting extremely small, layered particles of a mineral called albite, which is an integral party of moonstone’s composition. Albite are only a few hundred nanometers wide - small even by atomic standards. When light particles pass through the stone and encounter these tiny layers, they scatter.
Moonstone and the Blue Sky: A Scientific Connection
Here's where the secret of the blue sky comes in. The scattering of light inside moonstone is a perfect example of what's known as scattering. Because of their tiny size, the albite particles scatter blue light most effectively, reflecting it out of the stone and creating that stunning, seemingly internal blue flash. This is why the most coveted moonstone glows with an intense, captivating blue.
Interestingly, the same principle applies to our atmosphere. The air is filled with tiny nitrogen and oxygen particles, which are the perfect size to scatter blue light from the sun. When we look up, we see this scattered blue light, which is why the sky appears blue. So, the next time you admire a piece of moonstone jewellery, remember that the science behind its mesmerising glow is the very same reason our sky is blue.
A Note on Quality and History
Not all moonstones have this amazing adularescence. The most valuable stones with the strongest shiller effect often come from Sri Lanka. Deposits discovered there in the early 1900s led to a surge in its popularity, which is why you can find beautiful vintage moonstone jewellery from that period.
Whether you are looking for a classic gemstone ring or a beautiful pendant, moonstone offers a unique and ethereal elegance. Its captivating inner glow and the fascinating science behind it make it a truly special gemstone for any jewellery collector.
