********* practice

So due to recent illness my fingers are very swollen. De Wet Jewellers in Centurion mall assured me they will add more gold and resize my much loved diamond ring to make it larger. Size N to R. However when I collected it, despite the ring now being about 4 sizes larger, it weighed slightly less than when I had handed it in!! Upon querying this, the owner Marie de Wet insisted that that’s normal, saying the weight comes off in the polishing process! I’m so confused. How can they have added metal to a little ring and the weight becomes slightly less after it became much larger ring? Can anyone help me see the logic in this please?