Solitaires, mounted or loose diamonds, old and modern cuts: each stone is examined in front of you at 22 rue Drouot, with or without a certificate. Free first opinion within 24 hours.
A dealer on rue Drouot and a trained gemmologist, Ariel Altmann examines the stone itself — 10× loupe, gauge, precision scale — and values it at the day's international price. If you wish to sell, a firm offer follows, with immediate payment. See also our jewellery appraisal and signed jewellery pages.
Weight, colour, clarity, cut: the basis of any valuation. Then everything a report leaves out.
1 carat = 0.20 gram. Above the round thresholds — 1, 2, 3, 5 carats — the price per carat steps up.
From D, colourless, to Z. Read against a master set in daylight-balanced light, never by eye alone.
Inclusions read under a 10× loupe: their nature and position weigh as much as their number.
Proportions, symmetry and polish decide the brilliance. A modern round brilliant has 57 or 58 facets.
Under ultraviolet light. Strong blue fluorescence can lower the price of a top-colour stone, and lift a lower one.
A signed or period setting is valued in its own right. This is what a report never shows.
No. A laboratory report (HRD, IGI or another laboratory) helps the reading, but it is not required: the stone is examined itself, in front of you, at 22 rue Drouot.
On the four Cs — carat, colour (D to Z), clarity (FL to I3) and cut — read against the Rapaport price list published each week, then fluorescence, actual cut quality and the market for the piece it is mounted on.
Old European, cushion and rose cuts pre-date the 1920s–1930s. They are valued as they are, without any assumption of recutting, and are often worth most left on their period mounting.
Never before the opinion. A signed or period mounting can be worth more than the stone alone.
Send photographs of the stone and of any certificate by WhatsApp or e-mail; you receive a first opinion within 24 hours. The purchase itself takes place in Paris, with immediate payment.
Free and confidential appraisal, reply within 24 hours.
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