A Rockwell test will tell but if you try to file it and you can't or try grinding it and you get bright blue sparks off the parent metal its a good chance you have Titanium.
Titanium is stronger. Platinum can be used to make jewelry, so it can be formed and pounded into shapes. Titanium is much harder to machine and form into objects. .
Man, be more specific! If you are refering to titanium WHITE pigment than that is very cheap, it is used in housepaint and for artists. If you want titanium metal, i am curious as to what possible aplication you would want it for where aluminum would...