Summary for 18k white gold alloy content Discussion
18k white gold alloy content is the thread’s main question: Susan McKeever asks how to tell whether non-plated rings are nickel-based, platinum-based, or another mix, and how such rings wear over time. The only answer in the excerpt, from an unnamed contributor, says the easiest practical method is a nondestructive SEM analysis with an EDS detector. That setup can give a close estimate of the surface composition, but it only reads the surface, so any plating would mislead the result. The answerer suggests finding access through a university, hospital, or industrial lab, noting that these instruments are fairly common. The excerpt does not provide a direct answer about wear characteristics or the typical nickel percentage in white gold alloys, and it does not compare nickel versus platinum alloys beyond the testing method.
Q. I just picked up today from a casting company 2 wedding rings that I had cast in 18K white gold. We don’t plan on plating them. I like the “antique-y” white color. However, I just called the casting company here in NY to see what the alloy consisted of, since there was so much mention in this thread of the common mixture containing nickel. They couldn’t answer the question on the alloy mixture right away since they outsource it and asked me to call back later. Is there a way to tell if your non-plated 18K white gold ring is with a nickel based alloy or a platinum alloy or other? Also, any comments on how non-plated 18K white gold wears over time? Lastly, if it is nickel, what is the common amount in an alloy?
Thanks,
Susan McKeever
– Brooklyn, New York
2002
A. Susan, the easiest way I can think of is to use an SEM (yeah, I’m probably showing my nerd bias…) because it’s fast and most importantly nondestructive. The Energy Dispersive Spectrometer (EDS system) on most Scanning Electron Microscopes will easily tell you a pretty close estimate of the composition, but only of the surface: so a plating would fool the instrument.
You may have a friend at a university, a hospital, or in an industrial lab with access to an SEM- they’re surprisingly common. I do this sort of analysis for co-workers all the time.
Good luck!
Lee Gearhart
metallurgist – E. Aurora, New York
2002
Want Soft 18K Gold without Using Silver
Q. Is there a way to make 18k Gold without using Silver, and still keep it soft enough to put it under a rolling mill and bend to make bangles? Any shade of yellow gold would be okay.
Jayesh Ghaghada
– Dubai, UAE
March 28, 2018