Guide for jewelers

How to buy a diamond by certificate number

More and more jewelers arrive with a certificate number in hand: their customer saw it online, it came from an appraisal, or it was picked from a listing. This is how that number becomes a stone in your showcase.

What the certificate number tells you

The report number identifies one unique stone. With it you can look up online its 4Cs (carat, color, clarity and cut), exact measurements, fluorescence, polish, symmetry, the inclusion plot and, for lab-grown, the growth method. The same number is laser-inscribed on the stone's girdle, so certificate and diamond can be physically matched.

The process at Bamo, step by step

  1. Send the number. On WhatsApp at +52 81 1746 3849 or to [email protected], stating the laboratory (GIA or IGI).
  2. Verification. We look up the report on GIA Report Check or IGI Verify and confirm the specifications match what you need.
  3. Availability. We check whether the stone is in our Monterrey inventory or in the international supplier network. A certified stone is unique: if it has sold, there is no identical one.
  4. Quote. We send the price for that exact stone, with photo or video when the supplier has it available.
  5. Confirmation and delivery. On confirmation the stone is reserved. From local inventory it is delivered immediately; from the international network, typically in one to four weeks.

If the stone is no longer available

It happens often: a certificate number a customer saw online weeks ago may have sold. In that case we search for equivalents with the same shape, carat weight, color, clarity and cut, and send options with their own certificates so you can choose.

Tips when buying by certificate

  • Ask for measurements, not just weight. Two 1.00 ct stones can look different depending on depth.
  • Check fluorescence. "None" or "Faint" is safest for high color; strong fluorescence can affect appearance and price.
  • Match the inscription. On receipt, find the number on the girdle with a 10x loupe and compare it with the report.
  • Decide the laboratory first. See GIA vs IGI to choose by stone type.

Frequently asked questions

Can you source any certificate number?

If the stone is in our inventory or supplier network, yes. If it has already sold, we propose equivalents with the same specifications and their own certificates.

How long does a quote take?

We reply within 24 business hours; certificate verification is usually immediate.

Do you accept certificates other than GIA or IGI?

We work mainly with GIA and IGI. Other laboratories are reviewed case by case.

Can I see the stone before buying?

When the supplier has photo or video we send it. For stones in local inventory you can book an appointment at our office in San Pedro Garza García.

Looking for a diamond supplier for your jewelry business?

We work exclusively with trade professionals. Request access to the private catalog or message us on WhatsApp.