Refinishing a Dux lounge chair  

I recently bought a Dux lounge chair. The chair is listed in a Dux catalog which I have and it says the frame is made of walnut or teak. The problem is I am not sure whether it's walnut or teak. It seems the wood frame lacks the yellow/orange color other teak chairs have. But maybe the color fades only because of age?

So I have two questions:
1. Is there any simple way to tell whether the wood if walnut or teak?
2. It seems the chair is in oil finish. I've applied Watco teak oil on teak furniture before and got pretty satisfying results. I guess I can use it too if the chair is teak. But if the chair is walnut what kind of oil should I use?

If someone can give me some help I really appreciate it.