LMA Designs Boutique
New member
Hi! I recently have started testing my vintage / antique jewelry that I have been collecting. I got a brooch yesterday that looks very old. From the clasp type, the hinge, design, patina, I am deducing that it is from the mid to late 1800s. The brooch is unmarked. When I did a scratch test with 10k testing acid, it dissolved slowly and partially, leading me to believe that 9k gold was present. At first I thought plated, but there is a small wire type piece on the back that I thought, there would be no reason for it to be gold all the way through unless the whole thing was solid 9k. So I snipped a very tiny piece off for further testing and observed my cut. There is no other color but gold on the metal, I expected the core to be apparent base metal. I put my small snippet on my testing stone and applied 10k acid. It bubbled a bit, with a very light green reaction, which would be along the lines for 9k right? I would think the acid would eat out the non gold from the 9k alloy and leave the gold behind? I left the acid on there for quite awhile, expecting all the base metal to be eaten away and just to be some small gold (the assumed plating) left behind. Well, I became excited at the fact that my small snippet remained! And now it is shiny and gold colored. Am I right to assume this brooch is solid 9k? Edit to add: thank you so much for reading! Have a wonderful day!
