Refractive index
Index of Refraction ( Refractive Index or RI) is a value calculated from the ratio of the speed of light in a vacuum to that in a second medium of greater density.
The refractive index measure and determines how much the path of light is bent, or refracted when entering material.
The refractive index varies with wavelength, this causes white light to split into a lot of different colors, we called it dispersion of colors, which we can also observe, for example, on prism or rainbow.
Refraction Index can be measure with refractometer, and can be use for a lot of thing.
For example, to measure sugar content in fruit, or alcohol content on wine, and a lot of other stuff.
We will not bored you with a lot of formula and calculation, but basically, in gemstone, the higher the refraction index, the more "sparkle" or brilliance the gemstone will give, compare to the gemstone with lower refraction index.
This assume all the variable like smoothness of the stone, cutting angle, ect, are the same one to another.
Here we will provide you with the Index of Refraction in some of the Gemstone we know.
However, please note that RI is not everything in jewelry / gemstone.
If you like the most brilliance, higher RI is the way to go, but there always lots of other thing / variabes to look at in gemstone. Like the complexity of the colors, the pattern, ect.
Me personally will go to Aquamarine rather than diamond anyday.
Mossanite : 2.65 – 2.69
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Diamond : 2.417-2.419
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Cubic Zirconia ( CZ ) : 2.150-2.180
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Zircon : 1.810-2.024
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Ruby : 1.762-1.778
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Sapphire : 1.762-1.778
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Kyanite : 1.710-1.734
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Tanzanite : 1.691-1.700
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Malachite : 1.655-1.909
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Jade : 1.652-1.688
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Peridot : 1.650-1.703
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Apatite : 1.628-1.649
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Tourmaline : 1.614-1.666
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Topaz : 1.609-1.643
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Howlite : 1.586-1.605
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Emerald : 1.565-1.602
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Aquamarine : 1.565-1.602
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Labradorite : 1.559-1.570
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Amethyst : 1.544-1.553
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Rose Quartz : 1.544-1.553
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Adventurine : 1.544-1.553
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Citrine : 1.544-1.553
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Prasiolite : 1.544-1.553
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Quartz : 1.544-1.553
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Petrified Wood : 1.540
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Jasper : 1.540
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Chalcedony : 1.530-1.540
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Moss Agate : 1.530-1.540
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Orthoclase : 1.518-1.530
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Lapiz Lazuli : 1.500
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Calcite : 1.486-1.658
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Moldavite :1.48-1.540
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Sodalite : 1.480
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Fluorite : 1.434
