Understanding Jewelry Markings: 830 vs. 835 - What Do They Mean?

Question
Hi there,
Compliments of the day. Just two days back, I bought a white colored chain from Flea Market with 830 and 835 markings on it. Do you have any idea about those markings? For your better understanding, the chain is about 9 gms in weight with a locket marked with 830 on its metalic part. Further, there are two markings on the chain, one read as 830 on one side and, another 835 on other side of its hook (the part used to tie the chain). That day I also found a white colored locket marked with 575 on its metalic part (this locket contains a long bent stone; I don't know the name of the stone though).
Could you please give your expert opinion on these findings. I will be eagerly waiting for your kind reply.
Sincerely,
Mumu

Answer
Dear Mumu, again, these markings are not ones with which I am familiar.  My expertise deals with goods produced primarily in and for import into the USA, bearing marks associated with regulations of that country.

In Japan, I understand there are several different alloys of precious metals, made in proportions different that I am used to seeing or working.  I honestly cannot tell you what the markings mean.  However, if this represents some alloy of gold, the 830 is a high 19k, likely close enough in some regulations to call 20 karat. The  835 would actually be 20k, high enough to be considered that with close tolerance.  For instance, 24k (pure gold) x 0.835 = 20.04 karat.  I am not saying your chain is gold at all!  I am only showing you the possible relationship with the numbers and karat quality. You will have to research locally what karat levels of gold are generally available and what marks are used in a numerical system. Any jeweler should be able to quickly provide that information or you may find it on the Internet from a Japanese source.

You may want to check the numbers on the locket very closely. While 575 means nothing to me, 585 is the US and European standard mark for 14kt gold.

Sorry, I am not familiar with the Japanese system.  Perhaps the information will send you in a beneficial direction.

Peace and Blessings.     Thomas.