I found a couple wedding bands that said 18K on the bands, but the color was like that of a copper penny and ask around years ago and told these were marked this way as they were sold by traveling salesmen that sold them to those bachelors that wanted to get married and were not able to get to a jewlery store to buy one. I wonder sometimes if they were scammed, or knew they were not real.
Was told 18K and up were a soft gold and bend easy, I have a gold ring not marked I found that checks out on a hand tester that shows 14K but it bend easy. Jewler said he could test it but would have to take a piece and put it in acid to be sure, but didnt want to do that as he thought it was very old and high-quality gold. This came out of area that was hit hard with detectors and being it was loaded with pulltabs no one dug it. I was using my Minelab Sovereign with the Sun Ray 180 meter and read as a pulltab beaver tail on the meter 141-142 but sounded like a nickel 143-145 with the smooth tone they give. Being it was a weaker signal I thought it was deeper than most tabs and just had to dig it as it was different.