No, not all diamonds have a serial number. Only diamonds submitted to a gemological laboratory receive a laser-inscribed serial number matching their grading report. Vintage diamonds, ungraded stones, and accent diamonds typically have no inscription. Absence of a serial number doesn’t reduce what we pay, because our Westlake buying team evaluates every stone under magnification regardless of documentation.
What Is a Diamond Serial Number?
A diamond serial number is a microscopic alphanumeric code laser-inscribed on the diamond’s girdle, which is the narrow band running around the widest part of the stone. The inscription is invisible to the naked eye and requires a loupe or microscope to read.
The number corresponds directly to a grading report issued by a gemological laboratory, most commonly GIA (Gemological Institute of America), IGI (International Gemological Institute), or AGS (American Gem Society). When someone says a diamond is “GIA-graded,” they mean it was submitted to GIA’s laboratory, graded across the four Cs (cut, color, clarity, and carat weight), and issued a report. The serial number inscribed on the girdle matches the report number on that certificate.
The purpose of laser inscription is traceability. It allows a buyer or seller to match a specific stone to its grading report, confirming that the diamond being presented is the same stone that was graded. This matters most in high-value transactions where someone wants independent verification of the stone’s characteristics.
Which Diamonds Have Serial Numbers?
The short answer is: only diamonds that were submitted to a grading laboratory by someone who paid for that service. Laser inscription became standard practice for GIA-graded diamonds in the early 2000s. This means several large categories of diamonds typically don’t have serial numbers.
Vintage and antique diamonds almost never carry laser inscriptions. Old European-cut and old mine-cut diamonds from the Victorian, Edwardian, and Art Deco eras predate gemological certification by decades. Our antique diamond evaluators, who assess period cuts against era-specific collector criteria, provide a clear offer that reflects the value of those specific stones today.
Ungraded contemporary diamonds make up a large portion of the market. Many diamonds sold in jewelry settings, particularly at chain retailers, are never submitted to an independent laboratory. The retailer’s own quality description on the sales receipt isn’t the same as a GIA grading report. These diamonds have no serial number.
Small melee diamonds used as accent stones in halos, pavé settings, and side stones are never individually inscribed. They’re too small for the inscription process and are sold by weight and approximate quality range rather than as individually graded stones.
Diamonds sold before grading became common may have no documentation at all. A diamond purchased in the 1960s or 1970s, even a high-quality one, likely has no certificate and no inscription. Our vintage diamond specialists, who evaluate those stones under magnification through direct assessment, give you an accurate offer regardless of the documentation available.
How to Find a Diamond’s Serial Number
If your diamond has a GIA or IGI inscription, it will be on the girdle and readable under magnification. You won’t see it with the naked eye. A jeweler with a loupe can locate it in seconds. The number should match the report number printed on any grading certificate you have.
A few things to know before you look. The inscription is usually very small and may require 10x magnification to read clearly. On some stones, it can be hard to locate because the girdle is polished rather than faceted, making the inscription harder to read at certain angles.
If you have a GIA certificate but no inscription, it’s possible the stone was submitted before laser inscription was standard practice, or it was submitted. Still, no inscription was requested (it used to be optional). GIA inscriptions have been standard on their reports since around 2000, but you can verify whether your specific report includes an inscription by looking at the “additional grading information” section of the certificate.
What a Diamond Serial Number Does and Doesn’t Tell You
A serial number confirms identity. It tells you that the stone you’re looking at is the same stone that was graded and reported. That’s meaningful, particularly for high-value diamonds where substitution could theoretically occur.
A serial number doesn’t tell you how much the diamond is worth today. Grading reports reflect the stone’s characteristics at the time of grading, using that laboratory’s grading standards. Market prices for diamonds shift based on demand, supply, and economic conditions. A diamond graded in 2010 has the same characteristics reported on its certificate, but its market value in 2025 may be very different from what someone paid for it.
A serial number also doesn’t replace the evaluation. Our diamond grading team, who examine every stone under magnification before any offer, reads the stone directly and compares findings against any available documentation. We explain any discrepancies before presenting a number.
Does a Diamond Without a Serial Number Have Less Value?
No, not inherently. Value is determined by the stone’s actual characteristics: cut, color, clarity, and carat weight, plus any period or collector premium that applies. A high-quality old European-cut diamond from 1910, with no inscription and no certificate, can be worth substantially more than a mediocre modern brilliant with a full GIA report. The documentation reflects what was submitted for grading, not what the stone is actually worth.
That said, having a GIA certificate for a significant modern diamond does make the selling process faster and cleaner. It confirms the stone’s grade to a buyer without requiring them to take your word for it. Our certified diamond selling services, which handle both documented and undocumented diamonds in the same appointment, assess the stone directly and give you a clear offer based on what it actually is.
Selling a Diamond Without a Serial Number or Certificate
If you’re selling a diamond that has no GIA report and no laser inscription, that’s not a problem. We’ve been evaluating undocumented diamonds for decades, and the process is the same: we examine the stone under magnification, assess all four Cs directly, identify any period or designer characteristics, and connect the offer to current market pricing.
For inherited diamonds specifically, documentation is often missing or incomplete. Someone who received a ring in the 1960s rarely has the original grading report, and even if they do, a report from that era may not reflect current grading standards. Our inherited diamond evaluation team, which handles these situations every week, assesses the stone on its own merits and explains its findings before presenting any offer.
If you have a diamond you’d like formally documented before deciding whether to sell, our written appraisal services are available by appointment at our Westlake showroom. A formal written appraisal establishes the stone’s characteristics and replacement value, which is useful for insurance purposes or estate documentation. This is a separate paid service from the complimentary verbal evaluation we provide to every client.
Selling a Diamond Ring: Stone and Setting Together
Most clients selling a diamond are selling it as part of a ring, not as a loose stone. Whether you have a solitaire engagement ring, a diamond bridal set, or a diamond fashion ring, we evaluate the stone and the mounting separately and present both values before you decide.
Our diamond engagement ring evaluation, which covers the diamond first and then the metal mounting, gives you a full breakdown before you decide on anything. For rings where the setting has significant value, such as a platinum Art Deco mounting or a hand-engraved antique setting, we factor that into the offer separately.
For clients selling a gold-and-diamond ring, our gold ring evaluation team assesses the metal and the stone in the same appointment. You don’t need to separate anything before coming in.