Double Refraction

Moissanite has a property known as double refraction. Double refraction is when a ray of light passes through the gemstone, is slowed, bent, and split in two. Sapphire is a double refractive material as well, as are peridot, tourmaline, and zircon. To some degree, it is this property that gives Moissanite its amazing fire. While it is true that double refraction is a unique property of Moissanite, it is often viewed as a disadvantage by those who sell cubic zirconia. This is because critics claim that the double refraction causes the stone to appear blurry. However, this is not entirely accurate. While double refraction does cause a ray of light to split into two, every double refractive gem has an optic axis where the material behaves as a singly refractive gem. For Moissanite, this direction of single refraction is through the table of the stone. As such, the doubling is not apparent when the stone is viewed through the top (table). To see the doubling, the stone must be viewed at 10x magnification through any other crown facet, such as the star or bezel. Most of our customers are not aware of Moissanite's double refractive property, and we provide this explanation and images to demonstrate that while it is a unique property, it does not negatively impact its appearance.

Moissanite is cut so that this direction of single refraction is through the table. This means that the doubling is not apparent when the stone is viewed through the table (top of the stone). Moissanite must be viewed at 10x magnification (jewelers loupe) through any other crown facet (e.g. star, or bezel) to see the doubling. Most of our customers do not know or realize that Moissanite is double refractive, and we provide this explanation and images to explain that, although it is a unique property of Moissanite, it does not negatively affect its beauty.

We believe that the emerald cut Charles & Colvard created Moissanite is particularly useful in demonstrating its double refractive properties. Due to its long, straight lines, a step cut such as an emerald cut would make the doubling even more visible if it were readily apparent. However, as demonstrated in the accompanying video and picture, the doubling is not noticeable, further reinforcing the idea that Moissanite's double refraction is not a detriment to its appearance.