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TJ Gold & Diamond · tjdiamond.co
Manufacturer-direct engagement rings
Compare complete solitaire engagement ring prices for New Zealand and Houston. Every starting price includes a lab-grown diamond internationally certified by GIA or IGI and a classic solitaire setting in your selected metal.*
All taxes included · Free nationwide shipping
| Diamond | 10kt Gold | 18kt Gold | Platinum 950 |
|---|---|---|---|
| 0.50ct | NZ$999 | NZ$1,731 | NZ$1,904 |
| 1.00ct | NZ$1,519 | NZ$2,251 | NZ$2,476 |
| 1.50ct | NZ$2,211 | NZ$2,943 | NZ$3,237 |
| 2.00ct | NZ$3,251 | NZ$3,983 | NZ$4,381 |
| 2.50ct | NZ$4,463 | NZ$5,195 | NZ$5,715 |
| 3.00ct | NZ$5,676 | NZ$6,408 | NZ$7,049 |
| 3.50ct | NZ$6,715 | NZ$7,447 | NZ$8,192 |
| 4.00ct | NZ$7,927 | NZ$8,659 | NZ$9,525 |
All taxes included · Free nationwide shipping
| Diamond | 10kt Gold | 18kt Gold | Platinum 950 |
|---|---|---|---|
| 0.50ct | US$577 | US$999 | US$1,099 |
| 1.00ct | US$877 | US$1,299 | US$1,429 |
| 1.50ct | US$1,276 | US$1,699 | US$1,869 |
| 2.00ct | US$1,876 | US$2,299 | US$2,529 |
| 2.50ct | US$2,576 | US$2,999 | US$3,299 |
| 3.00ct | US$3,276 | US$3,699 | US$4,069 |
| 3.50ct | US$3,876 | US$4,299 | US$4,729 |
| 4.00ct | US$4,576 | US$4,999 | US$5,499 |
* Starting prices apply to a classic solitaire design. Micro-set, pavé, halo, hidden-halo, side-stone or customised settings may increase the final price depending on the design, number of diamonds and additional craftsmanship required. Any additional cost will be confirmed before manufacturing begins.
** The Buyback Guarantee is subject to TJ Diamond’s Buyback Guarantee terms, eligibility requirements and original purchase documentation.
*** Complimentary lifetime care includes professional cleaning, inspection, eligible resizing and rhodium plating, subject to TJ Diamond’s Lifetime Service and Guarantee terms. Accidental damage, excessive wear or third-party alterations may not be included.
**** If she does not love the ring, it may be exchanged for another ring of similar value within 30 days of collection at no additional charge. If the replacement ring has a higher price, only the difference is payable. Eligibility and condition requirements apply.
Buying a diamond should feel exciting, not confusing. This calculator gives you a transparent starting point for comparing lab-grown diamond prices. Choose the shape, carat weight, colour and clarity you're considering, and it will estimate a price for those specifications.
Lab-grown diamonds can offer exceptional value. A 1.00ct D colour, VVS clarity lab-grown diamond can start from approximately [USD $350], depending on shape, certification, availability and the characteristics of the individual stone.
All diamond prices on this page are in US dollars. Diamonds are traded internationally in USD — that's the currency the trade prices them in, wherever you are. Finished jewellery is charged in your local currency, and we'll always quote you in the currency you pay in.
Price should never be judged on the 4Cs alone. Cut quality, proportions, polish, symmetry, certification and how the stone actually looks all matter, and two diamonds with identical grades on paper can look noticeably different in person.
Use the calculator ABOVE as a guide, then talk to us if you'd like help finding a certified stone that suits your budget. Estimates only — prices move with market conditions, availability, shape and the individual stone.
Lab-grown diamonds are real diamonds. They share the same chemical composition, the same hardness and the same optical properties as mined diamonds. The difference is origin: they're created in controlled conditions rather than formed underground.
The main advantage is price. As production has improved and supply increased, high-quality stones have become far more accessible — which means you can prioritise size, colour, clarity or design without raising your budget.
But a lower price doesn't make every lab-grown diamond equal. Two stones with the same carat, colour and clarity can look noticeably different because of cut, proportions and light performance. Use price as one input, not the only one.
Because we manufacture in our own Auckland facility, we set the stone ourselves and can tell you honestly where spending more genuinely shows and where it doesn't.
Yes. Lab-grown diamonds are diamonds — the same chemical composition, hardness and optical properties as natural ones. The only difference is how and where they formed. Independent laboratories including IGI and GIA grade them using the same criteria.
At TJ Gold & Diamond, a 1.00ct lab-grown diamond solitaire engagement ring starts from NZ$1,519 in New Zealand and US$877 in the United States in 10kt gold. In 18kt gold, prices start from NZ$2,251 in New Zealand and US$1,299 in the United States. Platinum 950 starts from NZ$2,476 and US$1,429 respectively. Starting prices include the lab-grown diamond and a classic solitaire setting.
At TJ Gold & Diamond, a 2.00ct lab-grown diamond solitaire engagement ring starts from NZ$3,251 in New Zealand and US$1,876 in the United States in 10kt gold. In 18kt gold, prices start from NZ$3,983 and US$2,299, while Platinum 950 starts from NZ$4,381 and US$2,529 respectively. Starting prices include the lab-grown diamond and a classic solitaire setting.
Carat measures a diamond's weight, not its physical size. A well-proportioned 1.00ct round brilliant diamond is typically about 6.4–6.5 mm in diameter. Other shapes have different dimensions — for example, oval, pear, marquise and emerald-cut diamonds can appear larger or longer than a round diamond of the same carat weight.
The way a diamond is cut also affects how large it looks from the top, so two 1.00ct diamonds can have noticeably different dimensions and visual size.
Natural diamond pricing rests on geological rarity and the cost of mining. Lab-grown stones are produced in controlled environments, and as the technology has improved and competition increased, prices have fallen substantially. It's a supply story, not a quality one.
They may. Lab-grown pricing has moved a great deal as manufacturing has become more efficient. We'd rather say that plainly than pretend otherwise — buy a lab-grown diamond because it's beautiful and represents good value today, not as an investment.
Be realistic: resale values are generally well below the original retail price, and that's true across fine jewellery, not just lab-grown.
Which is exactly why we offer a buyback guarantee. We have bought back lab-grown diamonds since 2019 — we believe we were the first jeweller anywhere to do so, and we're not aware of another offering it today. Most jewellers who offer a buyback limit it to natural stones. We can commit to lab-grown because we manufacture our own pieces: the metal can be melted and re-used and the stone can go back into production. So if resale is the thing that worries you about lab-grown, we're the answer to it rather than a reason to hesitate.
Often not. D is the top of the D–Z scale, but many near-colourless stones look equally white once set, particularly in yellow or rose gold. If the setting is white metal and the stone is large, colour matters more. We'll show you the difference side by side rather than asking you to trust a grade on paper.
Usually not. VVS inclusions are hard to find even under magnification, and plenty of VS stones are completely clean to the naked eye. Dropping a clarity grade often frees up budget for better cut or more carat weight — which you will see.
Cut, and how the stone actually looks. A well-cut diamond will out-sparkle a poorly cut one with better colour and clarity grades every time. Grades describe a diamond; cut determines whether it performs.
No — it's an educational guide, not a quote. Diamond prices shift with availability, market conditions, shape, certification and the individual stone. For a firm figure on a specific certified diamond, contact us and we'll price it properly.
Yes. Tell us the carat, shape, colour, clarity or budget you have in mind and we'll compare certified stones with you — on specification and on appearance. Consultations are free and carry no obligation. You can book one here, or read how our custom design process works.