Acceptance & Submission Guidelines GEMSTONES
Gemstones Premium Positioning Authenticity - Quality At Catawiki we auction the best gemstones of premium quality which are hard to find and appealing to passionate gemstone enthusiasts. Because potential buyers come to Catawiki looking for special and rare gemstones, our in-house experts select every piece for our auctions, ensuring they are of premium quality and are presented in the best possible way. We do this because we aim to keep our bidders excited, allowing them to find the pieces they re interested in and ensure our sellers have great selling experiences.
At Catawiki, we move constantly forward. Our positioning is evolving to a strong premium segment which opens more opportunities for success for us and for you. From the 14 million visitors that come to our platform every month, we gain valuable information on what they are passionate about and what they prefer to buy. With your help, we want to make sure we continuously meet this demand and offer the special objects that our growing number of bidders are excited about and want to buy. In these guidelines, we ve defined what the special pieces are that bidders look for in our gemstone auctions. We ll also state what we require from you to successfully place them in auction. These guidelines serve to create a level playing field between all our sellers. We will be happy to make room in our auctions for your lots that meet this high quality demand, and we will aim to shape ourselves to better fit you. Our experts and account managers will be fully supporting and guiding you for success on Catawiki. Thank you for being with us on this exciting journey!
For our auctions we seek and select: Product Guidelines At Catawiki we auction gemstones gathered from all corners of the world. a wide range of natural gemstones and gemstones with selected standard treatments (or without treatments) gemstones that are in a decent condition and that have a sufficient quality in cut and clarity to be mounted in jewellery gemstones that are accompanied by a trusted gemmological certificate gemstones that have a minimum estimated lot value of 75 (as single stones, or, for selected gemstones offered as parcel)
Certified natural gemstones of premium quality For our gemstone auctions we seek a wide range of natural gemstones that are accompanied by a trusted gemmological certificate (see details further on). This includes: Beryl, all types (emerald, aquamarine, morganite etc.) Pearl, jade and other selected rare Corundum (all colours of sapphire, ruby) species, e.g. benitoite or taaffeite Tanzanite (and zoisite) Spinel (all colours) Chrysoberyl (incl. cat s eye and alexandrite) Opal (all crystal types, fire opals etc.) Garnet (all colours) Diaspore Grandidierite Tourmaline (all colours) Zircon (all colours) Peridot Topaz (all colours) Star corundum Amber, coral as well as lab grown gemstones (synthetic) Quartz (amethyst, ametrine, citrine) and composite gemstones are not suitable
Selection of uncertified natural gemstones Certain gemstones may be offered in a multiple stone lot, without a gemmological certificate. This only applies to gemstones that have an individual value below 100 and that comply with all other quality requirements. This also includes: Microcrystalline quartz (such as carnelian, jasper, tiger eye or petrified wood) Turquoise Lapis lazuli Rose quartz/rock crystal/smoky quartz Tourmalines Smoky quartz, rock crystal Moonstone
Faceted and cut gemstones For our dedicated Gemstone auction, we select faceted and cut minerals (gemstones), as well as polished minerals, e.g. cabochons, that are small and ready to be mounted in jewellery This includes cuts such as: brilliant, oval, emerald, pear, cabochon, marquise, cushion, trillion, square, princess, baguette, radiant, heart, fancy Any cut needs to be of decent quality, good enough to be used in jewellery. This is determined by e.g.: 1) Proportions (symmetry, crown height etc.) 2) Light performance (brilliance, windowing etc.) 3) Finish (polish) Gemstones that show low quality in all above criteria may be found unsuitable for our auctions Rough gemstones, slices, large carvings, spheres, balls, or eggs are more suitable for our Minerals auction
Clarity & condition For our auctions we accept gemstones that are undamaged and have a decent clarity. This means that the item submitted: may be transparent, translucent or opaque, depending on the gemstone - for some gemstones, the value strongly decreases if they are not transparent (such as tanzanite or aquamarine) may present inclusions (for example emerald could present inclusions) If the gemstone contains inclusions that affect the visual beauty of the gemstones (because the light cannot be reflected well or the colour is masqued by the inclusions), the expert can decide not to approve it. may have single small chips on girdle/facets or some signs of wear - these gemstones may be accepted (without a reserve price) as long as they are clearly disclosed in pictures and in the description
Accepted standard treatments The following standard treatments are accepted for selected gemstones: Heat treatment for corundum, tanzanites, citrine, amethyst, ametrine, zircon, tourmaline and pink topaz Oiling for emeralds Irradiation for blue topaz For jade: waxing (A-jade) or bleaching and impregnating with a polymer resin (B-jade) The following treatments are not suitable for our auctions: Materials such as emeralds, sapphires, spinels etc. that have had non-traditional coloured material such as dyes, coloured oils and coloured fillers (such as lead glass) Coating, as it might give a false appearance to the gemstone, (e.g. Mystic Topaz etc.) composites (such as doublets, triplets) beryllium (lattice) diffused (sapphires)
Authenticity / Certification Requirements Buyers are more likely to bid on your lot if they know it s certified as being authentic. This is why we ask to see certificates from trusted gemmological institutes for certain high valued types of gemstones. All gemstones generally valued at 75-100 or more require a certificate from our list of approved gemmological laboratories, as listed on the next slide. Sellers who have a degree in Gemmology may offer in the Certified Gemmologist Auctions without a certificate (after being approved by our experts) but, for gemstones valued above 950, they still need to add a gemmological report. Gemstones that have an individual value below 75 can be offered in homogeneous parcels (2 or more) to the Parcels of Gemstones auction, without a certificate.
List of suggested trusted gemological institutes Certificates of these laboratories are generally considered to carry sufficient details: GIA HRD IGI (Full reports Antwerp, India and Bangkok and Israel) IGE (Madrid) IGI (Istituto Gemmologico Italiano) Milano Gubelin GRS (Gem Research Swisslab) DSEF SSEF Lotus NEL (Leiden) LFG (France) AnchorCert (London) The London Gem and Pearl Laboratory CGL-GRS AGL WGI Certificates of the following laboratories may be accepted in certain cases: GIA (IL) (new option for sellers) AIG (Belgium) CGL-GRS IGI ID cards (India) Please be aware that we do not consider certificates of the following laboratories: AIG (IL) IGL (IL) EGL (Belgium) EGL (USA) CDG (IL) CGL (ILl) GIL (Bangkok & Israël) GECI CISGEM
Submission Guidelines Potential buyers are more likely to bid on lots with a good description, all relevant information displayed clearly and, of course, beautiful photos. Lot Description To help encourage potential buyers to bid on your lot, you should include a detailed description of your object(s). This should be thorough and honest, and follow the guidelines on the next page.
Lot Details If you are using our website to upload your lots, tips will appear to give you guidance about what information we need to know about your lot. The fields that you fill in help to present the information in a way that s easy for the buyer to read. Please use the additional description field to mention: The required information includes: Always provide overall information as given on the certificate, including Number of stones the report number in the description Type of gemstone The measurements, colour in detail, clarity and treatments as Individual gemstone weight these are not always mentioned in the reports Total carat weight Description of any imperfections The light sources used in the pictures (if other than daylight) Cut Shipping method Colour and clarity If you provide a country of origin which is not stated in the report, Treatment please clearly state this with the following disclaimer: Certification N.B. Country of origin is an opinion offered by the seller of this Country of origin item. This opinion is not substantiated by an official laboratory. Sealed yes/no If the report does not specify anything about treatment, please include: Treatments not investigated by this lab or This type of gemstone is commonly treated/heated (i.e topaz/citrine)
Photographs Submission Guidelines Including strong photographs is key to catching buyers eyes, ensuring they bid on your lot. Of course, buying online means potential bidders do not get a chance to see your lot in person, therefore detailed and high quality photographs are very important. To allow our experts, as well as our bidders, to get the right impression of an item, we require: a minimum of 3 close-up pictures, showing the gemstone from the top, bottom and side one clearly readable image of the certification report, where applicable
Image Guidelines Photograph your item in front of a plain, white background. Tip: You could use a white or black piece of A4 paper, folded in half and placed on a table in an L shape. Place the gemstone in the middle of your L-shaped paper and take your photos. Photos should show nothing else but the item(s) you want to put up for auction. Please also avoid any self-portraits or bare hands. Please always provide sharp close-up images of the back, bottom, top, and sides views of the gemstone. Use a macro lense if necessary. Please note that stock photos are no longer allowed and images should not be excessively enhanced. Include a clearly readable image of the paper certificate (not an online copy). Sealed gemstones require at least a clearly readable full picture of the front and back of the sealed certificate and paper certificate (not an online copy). Unless you can use professional lighting, make sure to photograph in daylight. Lamp light obscures an item s true colours, and flash photography can cause shading. Other light sources may be used but must be clearly mentioned. Do not use logos (from gem labs) in your pictures
Image Guidelines - Examples
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