Here is your answer.
The other replies are correct in that KRN does stand or the company mark.
BR is a standard stamp for brass. It is a soft and inexpensive metal. I recently purchased a set as well for the holidays as some fashion jewlery for my fiance.
If you high quality matters to you, you can take it to any jewler and have the stones re-set in silver, gold, or even platinum or palladium. It can get expensive so make sure you talk to a jeweler first, and bring the items with you.
