Contents
The black pearl And Newton's prism color and iridescence
The Science Behind Pearl Colors
The Role of Prisms in Light
The prism separates light into its different wavelengths, splitting white light into its component colors. Light passing through a transparent prism breaks down into six colors visible to the human eye. The prism systematically breaks down the different wavelengths of white light in the same way, resulting in the perception of six distinct colors.
Aragonite and Wavelengths
Aragonite reacts to several different wavelengths. Under white light, opaque material will always send back the same single wavelength resulting in the same single color. Because aragonite is transparent, more than one wavelength is sent back.
Constantly Changing Colors
A film of aragonite is, in fact, a network of conchiolin containing a huge number of aragonite crystals that pile up and form prisms, which are then covered over by a different substance. The sensitivity of these different components to a given wavelength causes the refraction of the corresponding colors.
Pearl's Deep Hue
A pearl’s deep hue comes from the thickness of its aragonite. Champagne, blue-gray, peacock, green, bronze, purple … it all depends on the variety of oyster and the richness of the nutritive elements to be found in the waters it lives in.
Interference and Iridescence
At the surface, interference of the different wavelengths causes iridescence. The transparent films of aragonite generate wavelength interference. This means that the eye sees several different colors simultaneously, producing the vibrating sensation known as iridescence.
