How to sell gemstones at Catawiki’s online auctions?

When you submit your gemstone items for auction, this is your opportunity to get people interested in your lots and encourage them to bid. 

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.


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.

The required information includes:

  • Number of stones
  • Type of gemstone
  • Individual gemstone weight
  • Total carat weight
  • Cut
  • Colour and clarity
  • Treatment
  • Certification
  • Country of origin
  • Sealed yes/no

Please use the additional description field to mention:

  • Always provide overall information as given on the certificate, including the report number in the description
  • The measurements, colour in detail, clarity and treatments as these are not always mentioned in the reports
  • Description of any imperfections
  • The light sources used in the pictures (if other than daylight)
  • Shipping method
  • If you provide a country of origin which is not stated in the report, please clearly state this with the following disclaimer: ‘N.B. Country of origin is an opinion offered by the seller of this item. This opinion is not substantiated by an official laboratory.’
  • 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)


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.
  • 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.
  • Please note that stock photos are no longer allowed and images should not be excessively enhanced.
  • Do not use logos (from gem labs) in your pictures

Image Guidelines - Examples


Now that you know exactly what you need in order to create a fantastic lot, it’s time to start selling your gemstones. Start submitting your special objects for auction.

We look forward to receiving your lots soon - our experts can’t wait to see what you have to offer!