[hollywoodrey]

I picked up a ring with a very nice Topaz that has a hallmark stamp "950".

Does anybody have an idea what this number could be referring too?

[thommyschnak]

In most cases the 950 stamp is referring to the amount of pure metal that your ring contains. In this case yours says 950 this means 950 parts pure platinum out of a possible 1000 parts. I would like to take the credit for this answer, but here is the site that I got my info from.Metal Stamp