I have been a jeweler with over 50plus years . I started as a polisher, then setter, Then I worked for 5 years casting and other aspects. I went to GIA starting in the late 70's and took refreshers and labs till 2000. I learned assaying of gold, silver, and platinum, and worked for many years buying, and then making gold bars which were sold every day and checked by my fire assay which was done the night before the bar was sold. I got very interested in finely made jewelry, antique jewelry, and popular manufacturer names and their correct markings. Now I use all the experience I've built up over 50 years to buy and sell.