The gold I am buying to make my jewelry is coming straight from the hands of small scale miners. Depending on the location gold purity runs anywhere from 80-97%. I need a way to test purity that’s more accurate than acid. The ability to know the rest of the metal content would be helpful as well. I’ve searched through the forums and the last time I saw this topic discussed was almost 10 years ago. In 2021 what are the best machines? I’m open to all suggestions and price ranges. Thank you for the help. I’m enjoying reading through all the information on here.
Ive been in the same situation, and I found that without sending the metal to a refiner, is best to dilute it with 50% newly refined gold. I was casting and fabricating combined. Treat it like reusing scrap. The material I was working with also a high quality raw ore - at least 18kt. It was a tough challenge working with it. It contained other metals including iron, copper and some rare earth metals.
The miner set it to a professional assayer. He was the client for a custom piece with his metal and gemstones for his wife.
To determine it’s characteristics I melted the ore into small pellets about the size of a fat lentil. While it was red hot I was used a steel stamp and mallet to stamp it. The other metals have the metal a brittle character in making and forming bezels (which I needed).
That’s when I did a mix of raw ore and new metal to keep our above 18kt for hallmarking.
It was a really interesting challenge.
Without sending it to a professional assayer service, because the are so many impurities possible… you are probably going to be wasting your time and energy.
Just a thought.
Thank you for your thoughtful reply, Eileen. My concern isn’t really working with the gold in the alloy as it comes out of the ground. I want to be able to stay competitive with what I offer the miners for their gold. There are a LOT of small scale miners in the area and the purity varies quite a lot from mine to mine. It’s common to buy quantities as small as a gram or two, so having an assay done really isn’t practical. I’m just smelting a little button with a torch and looking for a good way to test it. By chance do you have any experience with the refining part? I’ve seen a couple electro-refining setups that are pretty reasonably priced. I feel like there’s an opportunity to refine the local gold for local jewelers.
If you contact Shore International (ishore.com) they have refining equipment that is easy to use, excellent customer service. I have been refining for the past 3 years with there equipment.
Typo the website is ishor.com
Thank you for your reply, John. Are you using their aqua regia or saltwater system? What kind of cost per ounce are you seeing to refine?