How to Choose an Engagement Ring Setting

In a world where many retailers simply resell mass-produced items, TJ Gold & Diamond stands as a powerhouse of true creation. As one of the largest vertically integrated jewellery manufacturing companies, we don't just sell jewellery—we build it. From our state-of-the-art facilities to your doorstep, here is a behind-the-scenes look at how we master the art of manufacturing from A to Z, and why choosing a direct-to-consumer manufacturer is the smartest move for your next masterpiece. https://www.tjdiamond.co/en-nz/pages/manufacturing-process 1. Concept and 3D CAD Design Everything begins with a vision. Whether it’s a rough sketch or a detailed dream, our expert designers use high-end Computer-Aided Design (CAD) software to create a digital blueprint. This allows us to perfect the proportions and show you a photorealistic preview of your piece before a single grain of gold is melted. 2. High-Precision Resin Printing Once the digital model is perfected, we move into the physical world. Using advanced 3D resin printers, we create a high-resolution wax-like model. This ensures that the intricate details—the fine filigree and the precise stone seats—are captured with a level of accuracy that hand-carving simply cannot match. 3. The Casting House: From Wax to Gold This is where the magic happens. We operate our own casting house, allowing us to control the purity and quality of our alloys. Using the "lost wax" casting method, the resin model is encased in a flask, burned out, and replaced with molten 14k, 18k, or platinum. By refining our own metal, we guarantee the integrity of every gram. 4. Our Specialized Chain Factory One of the capabilities that truly sets TJ Gold & Diamond apart is our dedicated chain manufacturing factory. While most jewellers buy their chains from a third party, we manufacture our own. From classic links to complex designs, having this in-house ensures a level of durability and finish that is second to none. 5. Master Setting and Hand-Finishing Once the raw casting is complete, it moves to our master jewellers. Our stone setters use microscopic precision to secure each diamond and gemstone. Following the setting, the piece goes through a multi-stage polishing and finishing process. We don't stop until the metal has a mirror-like luster that reflects our high standards. 6. The Chemical Edge: In-House Rhodium & Refining Our expertise extends even to the chemistry of the trade. We manage our own refining and chemical production, including our own rhodium plating solutions. This vertical integration means we know exactly what goes into every layer of your jewellery, ensuring a brilliant, long-lasting white-gold finish that doesn't fade prematurely. 7. Strict Quality Control (QC) & Dispatch Before any piece leaves our facility for New Zealand, Houston, or beyond, it undergoes a rigorous multi-point QC check. We inspect the stone security, the prong integrity, and the overall finish. Only when it is perfect is it dispatched to our retail showroom or shipped directly to you. Why You’re Making the Right Choice When you choose TJ Gold & Diamond, you are cutting out the middleman. You aren't paying for a "brand markup"—you are paying for expertise, raw materials, and craftsmanship. Direct to Consumer: By manufacturing everything in-house, we pass the savings directly to you. Global Reach, Local Touch: With operations in NZ and Houston, we combine global manufacturing power with personalized service. Unmatched Capability: From CAD design to chemical refining, there is no part of the process we don't master. Ready to start your journey? Experience the confidence that comes with buying directly from the source. At TJ Gold & Diamond, if you can dream it, we can manufacture it. https://www.tjdiamond.co/en-nz/pages/manufacturing-process

When you research engagement rings, you will encounter two gold standards: 14ct (or 14k in US notation) and 18ct (or 18k). The number describes the purity of the gold as a fraction of 24 parts. Understanding what the difference actually means for a ring worn every day for a lifetime is worth spending five minutes on before you buy. What the Numbers Mean Gold type Pure gold content Alloy content Hallmark stamp 10ct gold 41.7% 58.3% alloy metals 417 14ct gold 58.3% 41.7% alloy metals 585 18ct gold 75% 25% alloy metals 750 22ct gold 91.6% 8.4% alloy metals 916 24ct gold 99.9% 0.1% trace only 999 The 750 stamp inside an 18ct gold ring means 750 parts per thousand (75%) pure gold. The 585 stamp inside a 14ct ring means 585 parts per thousand (58.5%) pure gold. Both are real gold. The question is how much. Colour — The Most Visible Difference The most immediately apparent difference between 14ct and 18ct gold is the colour depth of yellow and rose gold. 18ct yellow gold: Richer, deeper, more saturated yellow. The higher gold content produces the warm, vivid colour associated with high-quality fine jewellery. Develops a warm patina over decades of daily wear. 14ct yellow gold: Slightly paler, less saturated yellow. The higher alloy content dilutes the gold's natural colour. In direct comparison with 18ct, the difference is visible to most observers. 18ct rose gold: Warm blush warmth from the copper alloy, richer and more vivid than 14ct rose gold. No replating required. White gold (either carat): Both are typically rhodium-plated to achieve a white surface. The colour difference between 14ct and 18ct white gold is less visible in the plated state. Durability — The Counterintuitive Truth 14ct gold is technically harder than 18ct gold because the higher alloy content introduces harder metals into the structure. In practical terms, this means 14ct gold is slightly more scratch-resistant. However, this hardness advantage is often overstated. 18ct gold is more than durable enough for daily engagement ring wear and has been used as the standard for fine jewellery in most of the world for over a century. The hardness difference is meaningful in jewellery that will experience significant friction or mechanical stress, but a well-made engagement ring in 18ct gold worn in normal daily life will not show meaningful wear difference compared to 14ct over a realistic ownership period. 18ct gold is not softer in the sense that it needs to be treated differently. It is softer in the laboratory sense, meaning it yields at a higher applied force than 14ct. In daily wear, this distinction is not meaningful for most engagement ring owners. The Replating Question Yellow 18ct gold and rose 18ct gold never need replating. The metal surface is the actual gold alloy of the ring, not a coating. White 18ct gold is typically rhodium-plated to achieve a bright white surface. This plating wears with daily contact, typically requiring professional replating every 1-3 years. This maintenance requirement applies to white gold regardless of whether it is 14ct or 18ct. For a ring worn every day for decades, TJ Diamond recommends yellow gold, rose gold, or platinum over white gold, as these metals require no ongoing replating maintenance. Why Most US Retailers Use 14ct Gold The dominance of 14ct gold in the United States is a historical commercial standard. 14ct gold costs less per piece to produce (less pure gold), which allowed retailers to maintain higher profit margins while appearing price-competitive. In most other fine jewellery markets — New Zealand, the UK, Europe, and Australia — 18ct is the standard minimum for fine engagement rings. TJ Diamond uses 18ct gold as standard at every price point. For US buyers, this means the ring ships in the international quality standard at pricing that compares favourably with US 14ct retail prices, because TJ Diamond eliminates the retail markup layers between the Auckland workshop and the buyer. Browse our yellow gold engagement rings and  rose gold engagement rings — all in 18ct gold as standard. For buyers considering white metal, see our  engagement ring collection for the full range of metal options, or  contact us to discuss metal choices for your specific ring. Frequently Asked Questions   Q1: What is the difference between 14ct and 18ct gold? 14ct gold contains 58.3% pure gold, with the remainder made up of alloy metals such as copper, silver, zinc, or nickel. 18ct gold contains 75% pure gold with a smaller alloy proportion. The higher gold content in 18ct produces a richer, deeper colour in yellow and rose gold, and a more consistent white in white gold. 18ct gold is also less likely to cause skin reactions for buyers with metal sensitivities, as the lower alloy content means less exposure to nickel and other reactive metals. In terms of durability, 14ct gold is slightly harder due to its higher alloy content, but 18ct gold is more than sufficiently durable for daily engagement ring wear, and TJ Diamond has used 18ct gold as the standard for all engagement rings and wedding bands for this reason. Q2: Which is better for an engagement ring, 14ct or 18ct gold? 18ct gold is the better choice for an engagement ring for three reasons. First, richer colour: the higher gold content produces a deeper, more vivid yellow in yellow gold, and a warmer, more lustrous rose in rose gold. Second, better long-term appearance: 18ct gold develops a warm patina over decades of daily wear that enriches its character. 14ct gold develops a slightly more yellowish tint over time as the alloy composition ages. Third, metal standards: 18ct is the international standard for fine engagement rings in New Zealand, the United Kingdom, Europe, and Australia. Most Houston and US retailers default to 14ct at the same price point. TJ Diamond uses 18ct as standard at every price point. The extra gold content is included in TJ Diamond's price at no additional charge because it is the correct base material for a ring intended to be worn for a lifetime. Q3: Is 14ct gold real gold? Yes. 14ct gold is real gold. The carat number describes the gold purity as a fraction of 24 parts. 14ct gold is 14 parts gold and 10 parts alloy metals, making it 58.3% pure gold. 18ct gold is 18 parts gold and 6 parts alloy, making it 75% pure gold. 24ct gold is 99.9% pure gold. All three are real gold. The difference is the purity level and the proportion of alloy metals present, which affects colour, durability, and price. 14ct and 18ct are both common jewellery golds. 10ct gold (41.7% pure) is also produced, primarily in the United States, though it is at the lower end of what most international standards classify as fine jewellery. Q4: Does 18ct gold tarnish or need replating? Yellow 18ct gold and rose 18ct gold do not tarnish and never need replating. The gold surface is the actual metal of the ring, not a coating applied over a base metal. What appears as tarnishing on untreated gold is the natural development of a patina as the alloy metals in the surface slowly oxidise, which typically enriches rather than diminishes the appearance of yellow gold over decades. White 18ct gold is typically rhodium-plated to achieve a bright white surface. The rhodium plating is a coating that wears over time with daily wear, typically requiring professional replating every 1-3 years. For a ring worn every day for a lifetime, TJ Diamond recommends yellow gold, rose gold, or platinum over white gold, as these metals require no ongoing replating maintenance. Q5: Why do US jewellers use 14ct gold instead of 18ct? The dominance of 14ct gold in the United States is primarily a historical commercial standard that became entrenched in the 20th century. 14ct gold is harder and more scratch-resistant than 18ct gold due to its higher alloy content, which was historically cited as a practical advantage. It also costs less per piece to produce, which allowed retailers to maintain higher profit margins while appearing price-competitive. In most other fine jewellery markets globally, including New Zealand, the United Kingdom, Europe, and Australia, 18ct gold is the standard minimum for engagement rings. TJ Diamond ships 18ct gold rings to US buyers at prices that compare favourably with US 14ct gold retail prices, because TJ Diamond is a manufacturing-direct business without retail markup layers. Q6: What does 750 stamped inside a gold ring mean? 750 is the millesimal fineness stamp for 18ct gold, indicating that the alloy contains 750 parts per thousand (75%) of pure gold. It is the international hallmarking standard used in most countries outside the United States. Inside a gold ring you may also see 585 (14ct gold, 58.5% pure), 375 (9ct gold, 37.5% pure), or 916 (22ct gold, 91.6% pure). In the United States, the ct or k (karat) marking system is more common, so an 18ct ring stamped for the US market may show 18k or 18ct. All hallmarks refer to the same purity standards. A TJ Diamond 18ct gold ring will be stamped with the appropriate hallmark for its jurisdiction. Q7: Is 18ct gold more expensive than 14ct gold? Yes, 18ct gold contains more pure gold per gram than 14ct gold, so the raw material cost is higher. At equivalent ring weight, an 18ct gold ring costs approximately 20-30% more in raw gold content than the equivalent 14ct ring. However, the total price of a ring depends on many factors beyond the metal cost, including the diamond, the craftsmanship, and the retail model of the seller. TJ Diamond's manufacturing-direct model eliminates the retail markup layers that most US jewellers apply, meaning TJ Diamond's 18ct gold rings are often priced comparably to or below what US retailers charge for equivalent 14ct gold rings at retail. The higher quality metal is included at no additional retail premium. Q8: Can you tell the difference between 14ct and 18ct gold by looking at it? In many cases, yes. 18ct yellow gold has a richer, deeper, more saturated yellow colour than 14ct yellow gold. The difference is more apparent in yellow and rose gold than in white gold, where both are typically rhodium-plated to the same white surface. In isolation, most buyers cannot precisely identify whether an unmarked ring is 14ct or 18ct. In direct side-by-side comparison, the difference in yellow gold depth is usually visible to the unaided eye, with 18ct appearing noticeably more vivid and rich. Over decades of daily wear, the colour difference becomes more apparent as the rings develop their respective patinas.    

Both are independent, reputable certification labs. GIA applies slightly stricter standards for natural diamonds and is the most widely trusted globally. IGI is the standard certifier for lab-grown diamonds. TJ Diamond stocks both GIA and IGI certified stones and recommends GIA for natural diamonds and IGI for lab-grown. When you buy a diamond engagement ring, the certificate that accompanies it is your primary independent quality verification. Every diamond TJ Diamond sells carries either a GIA (Gemological Institute of America) or IGI (International Gemological Institute) certificate. This article explains what each certifier is, how their standards differ, and how to choose between them. What GIA and IGI Both Do Both GIA and IGI are independent gemological laboratories — they do not buy or sell diamonds. Their role is to assess the quality of diamonds submitted to them and issue a grading report documenting the four quality variables (cut, colour, clarity, and carat weight) to a defined standard. Neither lab has a financial interest in the grade the diamond receives. Both laboratories are accepted by jewellers, insurance companies, and diamond dealers globally. A GIA or IGI certificate accompanies the ring and can be used for insurance valuation, resale documentation, and independent quality verification. Both labs also provide online report verification tools where any buyer can confirm the certificate's authenticity by entering the report number. The Key Differences Factor GIA IGI Founded 1931 — oldest major diamond lab 1975 — largest by volume Grading standards More conservative, slightly stricter in middle grades Slightly less conservative in middle grades — same scale Natural diamond reputation Highest in the industry Well-respected, slightly below GIA for natural stones Lab-grown diamonds Certifies lab-grown, less common Industry standard for lab-grown diamonds Resale value (natural) Highest — GIA commands a premium Slightly below GIA on secondary market Resale value (lab-grown) Equivalent to IGI Equivalent to GIA for lab-grown Price per certificate Higher — premium for strict standards Lower — more accessible pricing Online verification gia.edu/report-check igi.org/verify Why GIA Is Preferred for Natural Diamonds GIA applies slightly stricter grading standards than IGI in the middle quality ranges (F-J colour, VS1-SI1 clarity). This means a GIA G VS2 natural diamond has been verified against a stricter standard than an IGI G VS2. In practice, two diamonds with identical certificate grades from different labs may not be identical stones. A GIA-graded stone at a given grade is more reliably within the stated grade range than an IGI-graded stone at the same grade. For natural diamonds where long-term resale value is a consideration, GIA is the preferred certificate. The secondary market for natural diamonds applies a modest premium to GIA-certified stones, particularly at the 1 carat and above level. GIA certificates are also the most universally accepted by US jewellers for trade-in or upgrade programs. Why IGI Is the Standard for Lab-Grown Diamonds The majority of lab-grown diamonds are IGI-certified, and IGI's lab-grown grading standards are well-established. GIA also certifies lab-grown diamonds, but GIA lab-grown certificates are less common in the market simply because most lab-grown diamond producers have standardised on IGI. Both are entirely appropriate for lab-grown diamond certification — the choice between them for lab-grown is less significant than for natural diamonds. Browse TJ Diamond's full selection of lab-grown diamonds — all available with IGI or GIA certification at equivalent quality grades to natural diamonds. What a Certificate Does Not Tell You A certificate documents grades — it does not show you what the stone looks like. Two diamonds with identical GIA grades can appear meaningfully different in person due to differences in specific facet arrangement within the grade range, inclusion placement (a cloud near the table vs an inclusion near the girdle), fluorescence character, and the individual proportions within the stated depth and table ranges. This is why TJ Diamond provides virtual consultations for every diamond: the certificate tells you what the grades are, and the consultation shows you what the stone actually looks like. For a complete explanation of what the 4Cs mean and how each affects a diamond's appearance, see our article what are the 4Cs of diamonds?. For an understanding of how certificate grades affect diamond pricing, see how much does a 1 carat diamond ring cost?. Browse our full engagement ring collection, or  contact us to ask about specific GIA or IGI certified stones and arrange a virtual consultation. Frequently Asked Questions Q1: What is the difference between GIA and IGI diamond certification? GIA (Gemological Institute of America) and IGI (International Gemological Institute) are both independent diamond grading laboratories that issue certificates documenting a diamond's cut, colour, clarity, and carat weight. GIA is the older and more established of the two, founded in 1931, and its grading standards are widely considered the most conservative and consistent in the industry. IGI was founded in 1975 and is the world's largest independent gem certification and appraisal institute by volume. Both certificates are accepted by insurance companies and jewellers globally. The primary differences: GIA applies slightly stricter grading standards than IGI in the middle quality ranges, and GIA certificates command a modest premium in the natural diamond resale market. For lab-grown diamonds, IGI is the more widely used certifier and their grading is well-regarded. Q2: Which certificate is better for an engagement ring, GIA or IGI? For natural diamonds, GIA is the more conservative and widely respected certification. A GIA-certified natural diamond with a given colour and clarity grade is typically graded to a slightly stricter standard than an IGI-certified diamond at the same grade, meaning a GIA G VS2 and an IGI G VS2 may not be identical stones even at the same certificate grades. For lab-grown diamonds, IGI has become the industry standard. The majority of lab-grown diamonds are IGI-certified, and IGI's lab-grown grading is well-established and widely accepted. TJ Diamond offers both GIA and IGI certified diamonds. For natural diamonds where long-term resale value is a consideration, GIA is generally preferred. For lab-grown diamonds, IGI is the standard choice and entirely appropriate. Q3: Does a GIA or IGI certificate guarantee diamond quality? A GIA or IGI certificate documents the diamond's measured grades at the time of grading — it is an objective record, not a guarantee of subjective quality. Two diamonds can carry identical GIA grades and appear meaningfully different in person due to differences in facet pattern, fluorescence character, inclusion placement (a cloud near the table vs an inclusion near the girdle), and the specific proportions within the grade range. The certificate provides the essential quality framework for comparison, but it does not replace in-person or virtual visual assessment. This is why TJ Diamond holds virtual consultations for every diamond before purchase — the certificate tells the buyer what the grades are, and the consultation shows the buyer what the stone actually looks like in the specific setting metal they have chosen. Q4: Is IGI trustworthy for lab-grown diamonds? Yes. IGI is the most widely used certifying laboratory for lab-grown diamonds and their lab-grown grading standards are well-established and consistently applied. The majority of lab-grown diamonds produced by leading growers are IGI-certified, and IGI certificates for lab-grown diamonds are accepted by jewellers, insurance companies, and resellers globally. GIA also certifies lab-grown diamonds and their grading is equally respected, though GIA lab-grown certificates are less common in the market. Both GIA and IGI lab-grown certificates use the same 4Cs grading framework as natural diamond certificates, with the addition of a notation indicating the diamond is laboratory-grown. Q5: Can you tell if a diamond is lab-grown from its GIA or IGI certificate? Yes. GIA and IGI certificates for lab-grown diamonds state explicitly on the certificate that the diamond is laboratory-grown, using wording such as "laboratory-grown," "lab-grown," or "synthetic" depending on the certifier and the year of certification. The certificate also typically notes the growth method (CVD or HPHT). A natural diamond certificate will not contain any such notation. The diamond's unique report number can be verified on the GIA or IGI online lookup tool, where the same information is visible. A buyer receiving a diamond with a certificate can therefore verify the natural or lab-grown status of any GIA or IGI certified stone independently and immediately. Q6: What does the GIA grading scale for diamond colour mean? The GIA colour grading scale for white diamonds runs from D (completely colourless) to Z (light yellow or brown). D, E, and F are colourless grades, visible as colourless to the naked eye in any setting. G, H, I, and J are near-colourless — appearing colourless to the naked eye in most settings, with slight warmth visible under magnification or in direct comparison with a D-F stone. K through Z show increasing visible warmth or yellow tint. For most engagement ring buyers, G or H colour represents the practical sweet spot: effectively colourless in the finished ring at a meaningfully lower price than D-F grades. The colour grade advantage of warm metal settings (yellow gold, rose gold) allows buyers to select H or I colour without visible warmth, saving significantly at any carat weight. Q7: How do I verify a GIA or IGI diamond certificate is genuine? Every GIA and IGI certificate carries a unique report number printed on the certificate. For GIA certificates, enter the report number at gia.edu/report-check to verify the certificate's authenticity and view the graded details. For IGI certificates, enter the report number at igi.org/verify to verify. The online record will confirm the same grades shown on the physical certificate. Most modern GIA and IGI certified diamonds also have the report number laser-inscribed on the girdle of the diamond itself (the narrow band around the edge), which can be verified under 10x magnification by any trained jeweller. TJ Diamond provides the specific certificate report number before any purchase is finalised, so buyers can independently verify the stone's grades before the ring ships. Q8: Do natural diamonds hold their value better than lab-grown diamonds? Natural diamonds have historically retained value better than lab-grown diamonds on the secondary market. Lab-grown diamond prices have declined significantly since 2020 as production technology has improved and production volumes have increased, reducing the price premium that early lab-grown diamonds commanded. As of 2025, lab-grown diamonds at retail are typically 50-70% below natural equivalents at the same quality grades. On resale, the gap is typically even larger. For buyers whose primary goal is a visually impressive ring within a defined budget, lab-grown provides the most stone presence per dollar. For buyers who specifically want a ring that holds secondary market value, natural diamonds remain the more conservative choice. TJ Diamond offers both natural and lab-grown diamonds with GIA and IGI certification, allowing buyers to make an informed choice based on their specific priorities.