“Why is platinum more expensive than gold?”
Platinum is a heavier and harder metal than gold, and the price per gram on the open market is higher. Also, it is much more difficult to work with and requires more highly trained craftsmen to make jewelry.
“Can a platinum ring be sized like gold?”
No. It’s a much different process and must be done professionally. It is not good for platinum jewelry to be sized, and therefore it is better to order the correct size.