DAN RIBACOFFInvestigations · Polygraph · Security
GIA Graduate Gemologist · Independent Appraisal

Diamonds & Gemology

Dan Ribacoff is a Graduate Gemologist of the Gemological Institute of America — valuing, authenticating and verifying diamonds and colored stones for private clients, estates and attorneys. The work is appraisal and verification only, which means the valuation is independent: there is no offer to buy behind it and nothing to gain from the number coming in high or low.

Services

Appraisal & Valuation

Insurance, estate, divorce and probate valuations prepared to a standard that holds up in negotiation and in court.

Estate & Inheritance

Full inventory and valuation of inherited collections, including identification of treatments, synthetics and misattributed pieces.

Authentication

Verification of certificates, laser inscriptions and stone identity — natural, treated or lab-grown.

Litigation & Loss

Expert valuation for insurance disputes, theft losses and matrimonial asset division.

Why an Investigator Ended Up in the Diamond Trade

The diamond business and the investigation business have the same central problem: someone is telling you what something is, and you need to know whether that is true. Certificates get swapped. Stones get substituted. Treatments go undisclosed. Lab-grown material enters the market represented as natural. Provenance on an estate piece is often a family story rather than a documented chain.

GIA training gives the technical foundation to answer those questions with instruments rather than opinion. Thirty-six years of investigative work gives the instinct to ask them in the first place.

The Four Cs, Honestly

Carat, color, clarity and cut are the standard vocabulary, and cut is the one that actually determines whether a stone looks alive. A well-cut stone one grade lower in color will outperform a poorly cut stone with a better paper grade almost every time. If you are shopping for a stone, judge the stone first, then check the paper — not the reverse.

Never buy a diamond you have not seen, from a certificate you have not verified, at a price you have not compared.

Where to Meet

Diamond and estate jewelry consultations are held at the Manhattan office — a short walk from the 47th Street diamond district — and at the Boca Raton office for Palm Beach and Broward County clients. Estate and probate valuations for Westchester and Long Island are handled from the Harrison and Garden City offices.

Dan Ribacoff at a New York industry event
New York City — the practice's home market for the diamond trade

Speak With Dan Ribacoff

Confidential consultations. Cases handled worldwide from offices in Manhattan, Long Island, Westchester, Boca Raton and London.