Before you start anything, it is important to learn some basics about diamonds and certification. You can of course rely on the professional jeweller to help you, but you will find that going in with that extra knowledge can be very useful. 

The 4 characteristics that are taken into account when grading diamonds are the 4C’s. They stand for carat, colour, clarity and cut. Carat is the weight of the diamond that is expressed in carats, where 1 carat equals 0.2 grams. Colour is the degree of colour you can’t see in a diamond and it is graded starting from D which is colourless to Z which is light yellow or brown. Clarity refers to the absence of inclusions and blemishes as a diamond without them are rare and that affects the diamond’s value. Last but not least, is the cut which refers to the proportions of a diamond and its finish which give the diamond the unique fire, brilliance and scintillation.

And the best way to make sure you have purchased the ideal investment diamond is choosing a certified diamond, with a certificate from a recognised laboratory worldwide. As laboratories unfortunately do not use the same grading standards, you need to choose the most reputable ones.

Antwerp is a global trading hub, but buying there follows a few practical steps that differ from a typical retail purchase. Start with due diligence: request a clear scan of the laboratory report and high-resolution photos or a short video of the exact stone. Ask the seller for the full grading report number so you can verify the certificate with the issuing laboratory. 

Delivery options are usually pick-up from Antwerp or insured courier delivery worldwide. Pick-up lets you inspect the stone in person and can lower logistics steps, but it requires travel or a local representative. Insured courier delivery is more convenient and offers door-to-door protection; check the carrier’s insurance, tracking, and signature-on-delivery requirements. For insured shipments, make sure the consignment note lists the inventory ID and certificate number and that insurance covers the declared value.

On receipt of the diamond, run a simple authentication checklist: compare the certificate number and details to the stone, confirm measurements and carat weight, inspect cut proportions and polish against the report, and check for any laser inscription. If you cannot judge the stone yourself, arrange an independent verification with a qualified gemmologist or a recognized laboratory; many investors request a third-party report before completing a transaction.

Practical protective steps include negotiating a written inspection or return window, considering escrow for large purchases so funds are released after verification, and insisting on a written inventory ID on all transport documents. These measures reduce risk with cross-border purchases and help preserve options to resell or certify the stone after purchase.

If you want to invest in diamonds, set your budget with investor priorities in mind rather than as a simple consumer limit. Think through allocation factors such as how diamonds fit within your overall portfolio, expected liquidity needs, storage and insurance, and the time horizon for the investment. These considerations will determine whether you prioritise a single larger stone, which can be harder to sell quickly, or several smaller stones that can be liquidated in parts.

Resale and liquidity considerations to weigh when setting your budget:

1. Carat and marketability: larger stones often earn a higher price per carat, but they attract a narrower buyer pool. If liquidity matters, consider splitting funds into two or three certified stones instead of one large purchase.
2. Certification and provenance: lab reports, inventory IDs and clear provenance increase resale appeal. Buyers and brokers value stones with traceable documentation because it reduces uncertainty at resale.
3. Cut, symmetry and finish: beyond the basics of the 4Cs, stones with strong cut proportions and neat polish retain better market demand, especially in mid-to-high investment tiers.

Seller evaluation checklist: request these items before transferring any funds

1. Laboratory report scan and report number so you can verify the certificate with the issuing lab.
2. High-resolution images and, where available, a video showing the exact stone and any laser inscription.
3. Inventory ID or stock reference and any provenance or prior sale documentation.
4. Written reservation and deposit policy, including whether deposits are refundable and what the inspection or return window is.
5. Shipping and insurance terms for delivery, or detailed pick-up procedures if collecting in person.
6. Written warranty or after-sale services and confirmation that independent certification is allowed during the inspection window.

Examples of practical investor language to use when talking to a seller: ask for a “certificate number verification” and a clear “inspection window with return conditions”. That phrasing helps ensure the seller provides the documentation and protections an investor needs. Framing your budget and checks this way turns a purchase into a verifiable investment decision rather than a standard retail sale.

Once you have the budget, you need to know that you don’t have to spend all your money in one diamond only. You could indeed split your budget into 2 or 3 diamonds in order to diversify your portfolio. Haven’t we always heard that it is always important not to put all your eggs in the same basket? Well that also applies to investments in diamonds as it may reduce risk and allow you to eventually liquidate part of your portfolio if needed.

BAUNAT is specialised in diamond jewellery and investment diamonds. BAUNAT’s team can answer any question you may have on the subject and guide you through the whole process.

Antwerp is more than a jewellery centre; it is market infrastructure whose scale matters to investors because of the concentration of trading floors and the volume that flows through them. The district hosts exchanges and bourses where buyers, sellers and brokers meet to trade wholesale lots, which affects liquidity for anyone looking to buy or resell larger quantities.

That concentration brings practical benefits. First, liquidity: high trading volumes make it easier to find buyers or comparable lots when you want to exit a position. Second, pricing signals: active wholesale markets create frequent transaction benchmarks you can use to assess fair value. Third, access to supply: working with reputable Antwerp suppliers widens your reach to wholesale lots and specialized inventory not usually visible on consumer retail sites.

For investors, a sensible approach is to prioritise diamonds with clear certification and traceable inventory provenance, and to favour stones that match common wholesale lot sizes and specifications. That alignment makes it simpler to compare offers and to approach exchanges or professional brokers when it’s time to sell. In short, Antwerp’s scale improves market access, liquidity and the frequency of pricing information - all useful when investing in diamonds.