Svarowski's sphere

Swarowski's crystal sphere performs the 'diamond trick'. Due to its diamond-like cut, the light incoming into it undergoes multiplied reflection inside the sphere, which happens at various angles, so that the light leaving the sphere is broken up into separate colours.

The phenomenon of multiple inside the sphere reflection is utilised here. Due to the high value of the refractive index for diamond a total internal reflection angle for this medium is the greatest for all known media and it is 24°. Proper cut of the diamond allows for 'catching' the light inside it, and when it finally leaves it, due to the high value of refractive index, it undergoes dispersion into different colours.

Although made of cheap pieces of glass, this belt buckle also breaks up colours. A cheap imitation of diamond, a cubic zirconia, zirconium oxide ZrO₂ , also has a high value of refractive index: 1.48 in comparison to 2.42 for a diamond.

The mirror on the bottom surface of the sphere multiplies the paths taken by the light and mixes colours. Both in the sphere and in the pyramid colours do not need to be basic complementary colours. We can see cyan and magenta.

It turns out that proper cut does not guarantee Svarowski's sphere effect. The glass has to have high refractive index. A sphere made of glass which has low refractive index, even with a mirror underneath, reflects light only at some angles.