Selling inherited diamond jewelry.

Inherited diamond jewelry is a different market than a modern engagement ring. Two reasons: antique cuts (Old European, Old Mine, transitional) are valued by collectors at a premium, not a discount; and the lack of a modern certificate doesn't hurt as much because the antique appeal is the value.

Old European Cut: round-ish stones cut by hand between roughly 1890-1930. They have a smaller table, larger crown, and more dramatic faceting than modern brilliants. Collectors and antique dealers pay premium for these because they cannot be reproduced — modern recutting destroys the character. A 1.0ct Old European in nice color/clarity can fetch the same price as a modern 1.0ct round, sometimes more.

Old Mine Cut: pre-1890 cushion-shaped stones, very chunky, very hand-cut. Even rarer than Old European, even more collectible. Don't recut these — recutting halves their value and erases their history.

Asscher and step-cut antique: original Asscher cuts (1902-1930) are sought after. Modern Asscher is a different cut. If you're unsure which you have, take it to a vintage-jewelry specialist, not a mall jeweler.

Path that works: photograph the piece front, side, and inside the band. Bring it to one or two reputable estate-jewelry dealers (Doyle & Doyle, Lang Antiques, Erica Weiner — or local equivalents). They specialize in the antique market and pay accordingly. Skip mainstream jewelers, who will offer you "modern stone of equivalent weight" pricing.

If the piece is signed (Tiffany, Cartier, Van Cleef, Fabergé), the brand value can be 2-5× the loose-stone value. Photograph any maker's marks inside the band. A signed Tiffany Old European might fetch $15,000+ where the loose stone alone would be $4,000.