The Tree of Life in colored sandstone, as described in the Kaballah. The colors are from "The Golden Dawn" by Israel Regardie.
The quarter (not included!) is shown in some of the pictures to give the model a visual scale. The sculpture is 10cm high (about four inches).
The four "color scales" of the Kabbalah (King, Queen, Prince, Princess) correspond to the four Kabbalistic worlds: Atziluth, Briah (or Beriyah), Yetzirah, Assiah (or Asiyah). If you're not familiar with the different scales or worlds, then the Queen scale (this one!) is what you want.
Here are links to all four sculptures: