The rainbow exemplifies the power of beauty. It is also a prime example of the illusory display that we experience as the physical world: It is patently not something real, but rather an ephemeral or transitory "object" produced by the interplay of light and water.
The rainbow is an amalgamation of light - a perfect harmonic combination which produces a symbol of supernatural beauty, promise, and enlightenment.
The eleven stones are considered an auspicious number that is a symbol of new beginnings.
11 stones of Multicolor Sapphire, Emerald, and a Ruby