Hi all, Looking to find out if anyone knows of any US mint backed bullion (or other mint) in 14k and/or 18k purity? I bought a fancy new electronic PM testing device (Ebay Bucks Wahoo!), and it requires calibration by 14k and/or 18k yellow gold. I can buy test ingots, but thought - why not find coins that everyone can recognize! No more scratch testing with acid! I'm doing enough business now, and this should pay for itself in the next couple years! Once I get it in, do some tests and get comfy, I'll post a review. Thanks in advance!
No, you won't find any coins minted at 14k or 18k. The whole point of a gold coin or bullion is to get a bunch of gold - 18k is only 75% pure (which means you've got a lot of extra weight in other things, usually copper or silver). At this fineness, you're talking about an electrum coin. There are quite a few ancient coins minted in electrum, but I wouldn't recommend calibrating a machine based on those - the fineness varied quite a bit. Your best bet is going to just buy the test ingots.
I knew it was a long shot for anything below 90%, but thought I'd ask. There's enough variety in this world that someone has to have something. I'd just like to have something internationally recognizable at karat purity for dealing with other folks - something they see, know and trust.
What are the size/weight requirements? Could you test it against a pair of random rings, or against those silly one-grain bars?
Any 14k and 18k metals will do. I just wanted something recognizable to others, since this will be used for business. The only requirement is reasonably flat so it sits on the plate. I will just buy some spec ingots for now, and keep hunting for spec karat coins.
Can you use a 14k or 18k ring? (though not really flat) or does it need to be a "certified" 14k / 18k ignot.
I'm trying to imagine what kind of tester you bought. Is it an XRF ? And does it absolutely have to be 14k or 18k ? I ask because because if you want a coin, a Netherlands ducat is 23.66 karats. And a US gold Buffalo is so close to 24k as to not matter.
No, I wish. I keep looking, but can't justify $5k "and up" for testing at this point. And beyond that, they need calibration regularly, and it's something that can't be done at home very well. I got a GemOro AGT3. They have a cheap ingot, I just wanted a coin. Heck, I *ALWAYS* want a coin.
I think Canada did some .500 and maybe .750 coins in the 1970s. The latter would be the equivalent of 18k.
Thank you! I actually found a 2016 Monkey $150 coin in 18k. I'll keep looking for others. I knew that there had to be something!
Just thought a jeweler would have charms (like for a charm bracelet) in 14K and 18K, and probably not too expensive.
According to the manual, you're supposed to scratch the surface of the test piece to ensure a clean surface. Hope you're not needing to use this on coins....
