Hello, i am a piece of rainbow. i have seven colours, they're red, orange, yellow, green, blue and violet. so i'm beautiful, right?

　　One colour of mine can symbolize a thing. for example, red is a symbol of revolution and blue is a symbol of the sky. but you can only see me after a rainy day because i'm from the lights' dispersion. so i'm very perfect. now people make some crystal ornament like me and they're expensive. so i'm sure they all love me--a piece of rainbow.