While the violin is made of flamed maple for the back and spruce for the top for 300 years, different kinds of woods were used for accessories. Their mechanical function requires a good resistance to traction (for tailpieces), to twisting (for pegs), or to wear (for fingerboards).
Before the industrial and colonial era, hard and fine grain european woods were used (apple tree,  plum tree). Some of them are naturally « greasy », and thank to their fine grain, it's easy to obtain an admirable polish.