Several Hong Kong jewellers sell IGI certified lab grown diamonds, Carat Club Co. among them, and the honest answer is that the certificate alone does not tell you which one to trust. Carat Club Co. certifies stones of 0.5ct and above through IGI, makes every piece to order in two to three weeks, and prices from HK$999. What separates the brands is how they answer the seven questions below.
Every jewellery brand in Hong Kong says roughly the same six things. Ethically sourced. Master craftsmanship. Timeless design. Exceptional value. Certified diamonds. A heritage of excellence, usually dating to a year that sounds impressive.
None of it is checkable. All of it is free to say. Which means it carries no information at all, and if you are choosing between brands on the strength of their About page, you are choosing on the basis of who hired the better copywriter.
So here is a different approach: seven questions that cannot be answered with adjectives. Ask them of anyone, including us.
1. Will you give me the full specification per stone, in writing, before I pay?
Carat, cut, colour, clarity, and the measurements in millimetres, for each significant stone. Both stones if it is a pair.
A bad answer is a total carat weight and a reassuring adjective. "1.0ct total, premium quality" is not a specification. A seller who will not itemise before the sale has a reason.
2. Exactly which stones are IGI certified, and which are not?
This is the single most revealing question you can ask, because the honest answer is almost never the flattering one.
Independent grading costs money. On a small stone it can cost more than the stone is worth. So any brand implying that every diamond in a piece full of tiny accent stones is individually certified is either doing something economically irrational or being slippery with words.
A bad answer is "all our diamonds are certified" with no threshold given. Push. Ask which specific stones, at what size, by which lab, and whether you get the report.
Our answer: diamonds of 0.5ct and above are individually IGI-certified. Below 0.5ct, stones are not certified by default, because grading them independently can cost more than the stone. Certification below that threshold is available on request. The rule applies per stone, not per piece, so in a piece with a 1.0ct centre and 0.1ct accents, the centre carries a report and the accents do not. On tennis bracelets, a certificate is not included in the base price and IGI is available on request at HK$350 per stone. IGI does the grading, Carat Club Co. includes the certificate.
That is a less impressive sentence than "all our diamonds are certified". It is also true.
3. What is the metal, precisely, including the parts I cannot see?
PT950. 18K. 9K. S925. Say the number.
And then ask about the components nobody markets: what is the earring back made of, what is the clasp made of, and is the white gold alloyed with nickel or palladium. A platinum post with a base metal back is still going to irritate a sensitive ear, and it is a common quiet economy.
A bad answer is "solid gold" or "hypoallergenic". Neither is a specification. Hypoallergenic in particular is a marketing word with no legal definition and no enforcement behind it.
4. Where does the price come from?
Not "is it a good price". Where does it come from. What is in it.
A brand with a boutique in a prime retail district is paying rent, staff, security and insurance out of the margin on the pieces that sell, and it is also carrying the cost of every piece that has sat in the window unsold for a year. That is not dishonest, it is arithmetic, and it is in your price whether anyone mentions it or not.
A bad answer is a permanent sale. If a piece has been discounted 60% since the site launched, the discounted number is the price and the original is set dressing.
5. Who is paying for your returns policy?
Ask this one and watch the room change temperature.
Returns are never free, and the numbers are public. The National Retail Federation puts the 2025 return rate on online sales at 19.3%: about one order in five comes back. The reverse logistics firm Optoro estimates the cost of processing a single return at around 27% of the item's purchase price, once you count shipping both ways, insurance, inspection, restocking, and the fact that it cannot be sold as new again.
Multiply those and returns consume something in the region of 5% of a retailer's revenue. Nobody absorbs that out of kindness. It is priced in, in advance, across every piece on the shelf. The same NRF research found that 72% of retailers now charge for at least some returns, up from 66% a year earlier. The industry has quietly conceded the point.
So a generous no-questions returns policy is not a benefit you are being given. It is a charge you are being levied. Decisive customers subsidise indecisive ones: if you research carefully, choose deliberately, order once and keep it, you are funding the person who ordered three variations, kept none, and sent them all back.
Our answer, and we know it reads as the harder line: Carat Club Co. does not offer general returns or unconditional exchange. Not to trap you, and not out of meanness. Because the only way to offer it is to raise the price of every piece we sell, and we are not willing to charge you for somebody else's indecision. We think you are perfectly capable of making a considered decision, and we would rather price for that than protect against the opposite.
What we do stand behind: one year of free repair, and a seven-day exchange if a piece arrives with a defect. If we get it wrong, we fix it, at our cost. Everything is made to order over two to three weeks, so nothing was sitting on a shelf and nothing goes back to one.
6. Am I actually being sold a diamond?
Lab-grown diamond, mined diamond, moissanite and cubic zirconia are four different things, and the first two are diamonds while the last two are not.
A bad answer uses "diamond simulant", "diamond hybrid" or "lab diamond" loosely and hopes you do not press. A lab-grown diamond is a real diamond with the same carbon lattice and hardness as a mined one. A moissanite is a different mineral. Anyone blurring that line is doing it deliberately.
7. Does the story change when I ask a hard question?
This is the one that catches everything the other six miss. Ask something inconvenient and watch what happens.
A serious seller answers the awkward question directly and tells you the unflattering thing, because they would rather you buy with your eyes open than come back angry. A storefront gets vague, changes the subject, or retreats into adjectives.
You are not really testing their diamonds. You are testing whether they will tell you something that costs them money. That is the only real signal in the entire category.
Where we sit, without the adjectives
Carat Club Co. is a Hong Kong lab-grown diamond brand. We hold no inventory and make every piece to order, which takes two to three weeks and is the main reason our prices are what they are. We use IGI, we certify at 0.5ct and above, and we say so rather than implying more. We repair free for a year and exchange defects within seven days. We do not take general returns, because funding them would mean charging you more. We ship to Hong Kong and fourteen Asia Pacific markets.
Apply the seven questions to us and to everyone else. If someone comes out better, buy from them.
The short version
Ignore the About page. Ask for the specification per stone in writing, ask exactly which stones are certified and which are not, ask what the metal is including the back and the clasp, ask where the price comes from, and ask who is paying for the returns policy, because it is you. Then ask one inconvenient question and watch whether they tell you the truth when it costs them something.
