Bizak & Co. · Miami · Since 1996
Bizak & Co.Jewelers · Est. 1996

Sell Diamonds · Nationwide, by mail

Sell your diamonds — read by a gemologist, priced on demand.

Loose or set, certified or not — mail your diamonds in with free insured shipping and a trained gemologist grades every stone on the 4Cs. Written offer at true market demand, same-day payment, or your diamonds back free.

Graded on the 4Cs Certified or not Insured FedEx both ways Same-day payment

Diamonds we buy

From a single loose stone to an inherited estate — with paperwork or without.

Loose Diamonds

Single stones and parcels, any shape — round, princess, emerald, oval, cushion and more.

Diamond Rings

Engagement rings, solitaires and set pieces. We value both the stone and the mounting.

Certified & Uncertified

GIA and other lab reports welcome — but our gemologist reads the stone either way.

Estate & Inherited

Full collections and older diamond jewelry, every era and every cut.

How your diamond offer is built

Every stone is graded in person by a trained gemologist — not weighed and guessed. We read it on the 4Cs: cut, color, clarity and carat.

From there, the offer reflects current wholesale and resale demand for that exact type of stone — because two diamonds of the same weight can be worth very different amounts. If you have a GIA or other certificate, it confirms the grade and can speed things up, but it's never required.

You see the full offer in writing before you decide. Accept, and you're paid the same day by bank transfer. Decline, and your diamonds come back to you free and fully insured.

Confused by the paperwork? Read our guide: HRD vs GIA certifications explained →

How it works

01

Request a kit

Tell us what you have. We email a prepaid, fully-insured FedEx label — you pay nothing to ship.

02

Drop it at FedEx

Pack it and drop it off. Insured door to door through IFS (In4Sure), signature required.

03

We grade & offer

A gemologist reads each stone on the 4Cs and emails a written offer with the reasoning.

04

Paid same day

Accept and you're paid the same day by bank transfer — or everything ships back free.

Frequently asked questions

Do you buy uncertified diamonds?

Yes — certified or not. Our gemologist grades the stone in person, so a certificate isn't required to get a firm offer.

Do I need a GIA certificate to sell my diamond?

No, but it helps. A GIA or other lab report confirms the grade and can speed things up. We read the stone on its 4Cs either way.

How do you price a diamond?

On the 4Cs — cut, color, clarity and carat — plus current wholesale and resale demand for that type of stone, assessed by a trained gemologist. You see the offer in writing.

Do you buy diamond rings and estate jewelry?

Yes — loose or set, single stones or full estates and inherited collections. We value both the diamonds and the piece.

How and when am I paid for my diamond?

The same day you accept the offer, by bank transfer. No consignment and no waiting.

Is my diamond insured when I mail it?

Yes. You ship on a prepaid, fully insured FedEx label through IFS (In4Sure), tracked, with signature required, both ways.

Ready to sell your diamonds?

Request a free, insured shipping kit — no obligation. See your written offer before you decide.