So many times I am asked by potential customers, "is it stamped 14K, etc." This has caused me to include in my listings that the item is properly marked.
Here is the catch........an unscrupulous seller can easily obtain from a jewelry supply house a set of stamps for around $20 and mark any item any way the want.
Know your seller and check the feedback and ask for guarantees or do not buy....it is that simple!
(the fact that Ebay is running someone's listings for stamping materials next to this is very ironic, but now you see what I mean!)