Although alabaster can be white, brown or black, when people refer to alabaster, they are usually talking about the white, translucent version.
They may also be referring to something that is the color of white alabaster. Because of its color, white alabaster has often been considered a symbol of purity.
It can represent innocence and purity in a dream.
Alabaster is a valuable mineral. Therefore, in a dream it can represent something that is valuable and precious to you because of its purity.
The breaking of something made of alabaster in a dream can symbolize a loss of innocence.