Okay, this is ridiculously simple and sort of "why didn't I think of that". Such a beautiful effect and very easy. Tutorial is in Russian but the pictures explain it all. By a blog called Все о полимерной глине which translates to "All of Polymer Clay".
Wood Pendant, Tree of Life Pendant, Wooden Jewelry, Wooden Heart Jewelry, Tree of Life Necklace, Heart Pendant, Wood Carved Pendant