Sell your diamonds

Work directly with one of our GIA Graduate Gemologists to receive a personal evaluation and a highly competitive offer for your diamond, engagement ring or estate jewelry. Long Island's largest diamond buyer since 1910, we make selling private, simple, and rewarding.

Get a valuation

How it works

Four steps, and you can stop at any of them. Most sellers have an answer the same day they visit.

Step 1

Send us the details

Fill in the form below with the carat weight, shape and any laboratory report (GIA, AGS) you have, and add photographs of the stone and its mounting. The more you can tell us, the closer our estimate.

Step 2

Receive a ballpark range

We call or email you with a range based on what you have sent. A firm offer always requires examining the diamond in person.

Step 3

Schedule an appointment

Schedule an appointment at our Garden City showroom and we will make you an offer on the spot.

Step 4

Get paid, consign, or trade up

Accept and we pay by check on the spot. Prefer to wait for the highest price? Leave it with us on consignment. Or take the value as credit toward anything in the showroom.

Why sell to us

H. L. Gross & Bro. is Long Island's largest diamond buyer. We have been buying and selling diamonds in Garden City for decades, and we buy for our own clients rather than to pass along to a wholesaler, so the offer you hear reflects what your diamond is worth here.

  • A GIA Gradudate Gemologist grades your diamond and makes the offer, in person
  • The highest prices in the New York area
  • Paid by check on the spot
  • Consignment for sellers who want the highest price
  • Full trade-in value toward anything in the showroom

840 Franklin Avenue, Garden City · 516-747-6666

Two ways to sell your diamond

Choose the route that suits you. We will explain both when you visit, and there is never any obligation.

Option 1

We buy your diamond on the spot

We make you a cash offer to purchase your diamond outright. Accept and you leave with a check the same visit. Simple, private and immediate.

Option 2

Sell your diamond on consignment

If you do not need the money right away and want the highest possible price, leave your diamond or engagement ring for sale in our showroom. We agree a price with you beforehand, and once it sells we pay you via check.

What we buy

Loose stones or mounted, certified or not. If you are unsure whether your piece qualifies, send it to us anyway — we will tell you honestly.

Loose diamonds Engagement rings Diamond studs & earrings Tennis bracelets Diamond necklaces & pendants Wedding & anniversary bands GIA & AGS certified stones Estate & antique diamond jewelry Fancy shapes & fancy colors Designer diamond jewelry Gold & platinum jewelry Diamond-set watches

Get a valuation

Tell us about the diamond and we will come back to you within two business days with a range.

Or, schedule an appointment now.


We only buy from sellers in the United States with valid identification. A ballpark range is not a firm offer — we confirm every purchase in person.