I make necklaces with fossil pterosaur teeth, 95 million yrs old, look great, only problem is the cost of the fossil in the first place, they are about £30-£40 for a good one
I tried with other teeth but generally they don't look like teeth so it might well be a tyrannosaur but it just looks like rock to most.
Ive just had a tooth out myself and was thinking of making a necklace out of that, not sure if I could sell it though...