Q:

Is it possible for wands to be made of more than one type of wood without them being blended together?

I'm pretty sure that wands can be made of a blend of more that one type of wood but do any wand makers make a wand with different parts made out of different types of wood? (e.g. The wand base being made out of redwood and the rest in elder)
If that is something that some wand makers do, then does Ollivander do that?

A:

According to the Harry Potter: The Wand Collection factbook, Nymphadora Tonks's wand was carved from two distinct magical woods, giving it a unique striped effect.

Tonk's wand is carved of two different woods, with a striped shaft
  that opens into a jack-in-the-pulpit flower.

