Submission guidelines · Jewellery

Jewellery: what we accept

We accept professionally made fine jewellery with a minimum value of €100–200, depending on the type of piece. Every submission is reviewed by an Auctium jewellery expert before it can go live — follow these guidelines to give yours the best chance.

What we accept

• Professional manufacture — a refined finish, skilful execution and construction built to last.
• Precious metals and stones meeting the material standards below.
• Ethical sourcing: diamonds must comply with the Kimberley Process; coral and other organic materials fall under CITES rules.
• Pieces with diamonds or gemstones estimated above €5,000 always need a laboratory certificate (see proof of authenticity below).

Brand jewellery must additionally be made by an internationally recognised house with an established reputation, be signed with its registered trademark, and be in new or pre-owned condition — think Cartier, Bulgari, Van Cleef & Arpels, Tiffany, Boucheron, Chaumet, Pomellato, Mikimoto and comparable maisons.

Material standards

Minimum metal weights apply: gold or platinum with stones from 1 gram, without stones from 1.5 grams, and 8–10 kt gold from 4 grams.

Natural colourless diamonds are accepted in colours D–Z and clarity up to I1/I2 where inclusions don't spoil the stone. Lab-grown diamonds are accepted only with a laboratory certificate stating their origin, from VS2 clarity and D–F colour and a 1 ct minimum. Gemstones must be in good condition with all treatments disclosed: heating, oiling and fracture filling are fine when declared; dyeing, drilling, glueing, doublets, reconstituted stones and treated opals are not. Pearls must be cultivated saltwater varieties (Akoya, Tahitian, South Sea) in natural colours and pristine condition. Amber, ivory, ebony, tortoiseshell, bamboo and apple coral, and imitation pearls are never accepted; freshwater pearls only in combination with gold or high-value natural gemstones.

Reserve price rules

Jewellery valued below €300 is listed without a reserve price. Above €300, our experts agree any reserve with you at a level supported by past auction results and current demand — and may ask to lower or remove a reserve that has repeatedly prevented a sale.

What we do not accept

• Jewellery in non-precious metals, or gold-plated silver outside dedicated silver auctions.
• Hobbyist or poor craftsmanship, and pieces that are visibly worn or damaged.
• Lab-grown diamonds presented as natural, synthetic stones or simulants (unless antique and period-correct), dyed or reconstituted stones and treated opals.
• Fashion or commercial costume jewellery (e.g. Swarovski-style lines).
• Any piece with diamonds or gemstones estimated above €5,000 without certification.

Required details

The submission form guides you through the essentials — complete every field so your listing is searchable and easy to bid on:

• Brand and model — the maison and the collection or line, where applicable.
• Metal — type, fineness and total weight in grams.
• Stones — type, carat weight, cut, colour, clarity and any treatments.
• Certificates — which laboratory reports or certificates accompany the piece.
• Year and condition — period and an honest grade, including any restoration.
• Description — sizes in mm/cm, hallmarks and signatures, provenance, packaging and any flaws.

Photos

Upload 6–8 high-quality images on a neutral background, in natural light, without filters or digital editing. Your set must show:

• A 360° view: front, back, sides and top.
• Hallmarks, maker's marks and serial numbers, readable.
• Close-ups of key details — and of every flaw.
• The full certificate or lab report, legible.
• The jewellery box only if it is included in the sale.

Proof of authenticity

For pieces whose diamonds or gemstones are estimated above €5,000, a certificate is mandatory. A report covering the centre stone is sufficient — unless the piece combines a centre stone with side stones totalling over 1 ct, in which case we need a full jewellery report covering all stones. We accept reports from approved gemmological institutes, including GIA, IGI, HRD, SSEF, Gübelin and AGL. Our experts may request a lab report at any time when a material, origin or treatment is uncertain.

For brand jewellery we may additionally ask for the certificate of authenticity, proof of provenance, and the original invoice or packaging.

A description that sells

Name the metal and its fineness, every stone with its 4Cs, the exact size, the hallmarks, and the certificate numbers. State restorations and flaws plainly — bidders reward honesty with confidence.