What will Cause Pearls to be Different Colors? | TPS Blog
The material which comprises a pearl, called nacre, is secreted by an oyster as a response to an irritant on the inside of the shell. Natural pearls are very expensive and rare and comprise of concentric layers of nacre surrounding a potentially microscopic original irritant, like a piece of sand. A cultured pearl is made by presenting a shell nucleus, usually perfectly round, and permitting a ...
