This is a rainbow-coloured sphere. It is difficult to say what colour it is; from one side it is honey-yellow, from the other green, from the top it is bluish. And if you spin it the colours change.

The colours in the sphere (or in a similar structure resembling a pyramid) are not basic colours. For example there is no red. These colours are compounds (sums) of two basic colours. Such is the case with cyan; it is a mixture of blue and green.

This heavy glass ball cut in the shape of a football ball delights us with a range of colours depending on the angle from which we look. It looks like rainbow or even better.

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.