Found SJM stamped inside your jewelry?
That's our mark. SJM is the maker's mark of S&J Diamond Corp, stamped into every piece we manufacture. Here's what it means and how to read it.
SJM is our maker's mark.
S&J Diamond Corp has manufactured fine jewelry out of New York's Diamond District since 1995 — bridal, fashion, and signature pieces in diamond and colorstone. Every piece that leaves our workshops carries the SJM stamp as a record of who made it and stands behind it.
It sits alongside the metal-purity stamp required by law, so you'll typically see it as a pair — something like SJM 14K, SJM 18K, or SJM 585. SJM identifies the manufacturer; the number identifies the metal.
Usually inside the band, or on the clasp.
On a ring, check the inside of the band. On a bracelet or necklace, check the clasp or a tag near it. On earrings, it's typically on the post or the back of the piece. The stamp is small — a loupe or jeweler's magnifier helps.
We don't sell directly to consumers.
S&J is a trade-only wholesale manufacturer — we supply fine jewelry retailers, we don't run a storefront ourselves. If you own a piece stamped SJM, it reached you through one of the retailers we supply. Read more about our story and how we source and manufacture every piece.
What does SJM mean on jewelry?
SJM is the registered maker's mark of S&J Diamond Corp, a jewelry manufacturer that has worked out of New York's Diamond District since 1995. We stamp it into every piece we manufacture as a record of who made it.
Is SJM a hallmark or a metal-purity stamp?
It's a maker's mark, not a purity stamp. You'll usually find it stamped right next to the metal-purity mark required by law — for example “SJM 14K,” “SJM 18K,” or “SJM 585” — with SJM identifying the manufacturer and the number identifying the metal.
Where is the SJM stamp usually located?
It depends on the piece. On a ring, look on the inside of the band. On a bracelet or necklace, check the clasp or a tag near it. On earrings, it's typically on the post or the back of the piece, alongside the metal stamp.
Can I buy directly from S&J Diamond?
No — S&J Diamond is a trade-only wholesale manufacturer. We don't sell to consumers directly. If you own a piece stamped SJM, it reached you through one of the fine jewelry retailers we supply.
How do I get more information about a piece stamped SJM?
For questions about a specific piece — repairs, appraisal, or warranty — start with the retailer where it was purchased. If you're trying to confirm authenticity or track down which retailer might carry it, email us at sales@snjny.com and we're glad to help where we can.