What is a Sovereign in Jewelry?

Getting the ring size right before ordering is one of the most practically important steps in buying any ring and one of the most commonly mishandled. This guide covers three methods for measuring ring size at home, ranked by accuracy, plus the five most common mistakes that produce incorrect measurements even when the method is followed correctly. The most accurate sizing is always taken in person at TJ Diamond's Auckland studio using calibrated metal sizing rings. At-home methods are good for planning and approximate sizing. For any ring intended for daily wear confirm the size in person before crafting begins. New Zealand Ring Sizing — The UK Letter System New Zealand uses the UK ring sizing system: letters rather than numbers. The most common NZ women's sizes are L to N (US 5.75 to 6.75). The most common NZ men's sizes are S to V (US 9.25 to 10.75). These are population averages  always measure the specific finger. NZ/UK Size US Size (approx) Circumference (mm) Diameter (mm) J 4.75 48.7 15.5 K 5.25 50.3 16.0 L 5.75 51.9 16.5 M 6.25 53.5 17.0 N 6.75 55.1 17.5 O 7.25 56.6 18.0 P 7.75 58.3 18.6 Q 8.25 59.9 19.1 R 8.75 61.4 19.6 S 9.25 63.0 20.1 T 9.75 64.6 20.6 U 10.25 66.2 21.1 V 10.75 67.8 21.6 W 11.25 69.4 22.1 Featured snippet target: "ring size chart NZ" — this table with NZ/UK letter, US size, circumference and diameter is what Google surfaces for this query. Method 1 — Paper Strip (Most Accurate) Cut a strip of paper approximately 1cm wide and 15cm long. Wrap snugly around the base of the correct finger tight enough not to slide over the knuckle, not so tight it creases the skin. Mark where the paper overlaps. Lay flat and measure the distance in millimetres. Find the millimetre circumference in the table above. That is your NZ/UK ring size. Measure in the evening fingers are at their largest in the evening and smallest in the morning. A morning measurement consistently produces a size too small. Method 2 — Existing Ring (Good Accuracy) Use a ring that fits the correct finger comfortably  on the same hand, same finger as the new ring. Place flat on paper, trace the inner circle. Measure the inner diameter in millimetres. Find the diameter in the table above. Note: ring size differs between the left and right ring finger. Always measure the specific hand and finger. Method 3 — String (Least Accurate) Wrap string around the finger and measure. String compresses under tension and gives a reading 1-3mm smaller than the actual circumference. If using this method, add 3mm to your measured length before looking up the size chart. Use as a rough starting point only. The Five Most Common Sizing Mistakes Measuring in the morning: Fingers are at their smallest. Produces a size too small. Measuring in cold temperatures: Cold contracts fingers. Measure at normal room temperature. Not checking knuckle clearance: The ring must pass over the knuckle. If the knuckle is significantly larger than the base of the finger, size to the knuckle. Measuring the wrong hand or finger: Left and right ring fingers are different sizes. Measure the exact finger the ring will be worn on. Taking only one measurement: Finger size fluctuates. Take three measurements at different times of day and use the middle value. Band Width and Sizing A wider band feels tighter than a narrow band at the same nominal size. If ordering a band wider than 4mm, consider sizing up half a size. TJ Diamond jewellers account for band width when taking measurements in person  this adjustment cannot be captured by circumference measurements alone. Surprise Proposals — Ring Size Without Measuring If a measurement is not possible before proposing, borrow a ring your partner wears on the ring finger of the left hand, trace the inner circle, and measure the diameter. Alternatively, ask a close family member. The most common NZ women's engagement ring size is N (approximately US 6.75)  but this is only an average. For any uncertainty, choose a plain solitaire or a half-set design that can be resized after the proposal. Browse our engagement rings and wedding bands  or book a studio sizing appointment at our Auckland studio before your ring is made. Our lifetime warranty includes one complimentary resize within the first 12 months for any TJ Diamond ring. If you are choosing a simpler design with maximum versatility, see our solitaire engagement rings collection  solitaires are the easiest engagement ring design to resize after a proposal. Related: What is an eternity ring?  Frequently Asked Questions   Q1: What ring sizing system does New Zealand use? New Zealand uses the UK ring sizing system, which expresses sizes as letters rather than numbers. The scale runs from A (smallest commercial size) upward, with half sizes expressed as a letter and a half (for example, M or M½). This differs from the US system (which uses whole and half numbers like size 6 or 6.5) and the European system (which uses millimetre circumference). When ordering from TJ Diamond, you can provide your size in NZ/UK letters, US numbers, or millimetre circumference — our team will confirm the correct conversion before your ring is crafted. Q2: What is the most common ring size for women in New Zealand? The most common NZ/UK ring sizes for women are L to N, which corresponds to approximately US sizes 5.75 to 6.75 and a finger circumference of approximately 51.9mm to 55.1mm. However, ring size varies considerably between individuals and is not reliably correlated with height, weight, hand size, or any other physical characteristic. Population averages are a starting point for a surprise purchase when no measurement is possible — they are not a substitute for actual measurement. For any ring intended for daily wear, TJ Diamond recommends measuring the specific finger in person at our Auckland studio. Q3: Can I measure my ring size at home without any tools? A rough estimate is possible without tools, but not a reliable measurement for a fine ring. Without tools, you can wrap a piece of string or a strip of paper around the finger and mark where it overlaps, then measure that length. The paper strip method is more accurate than string because string compresses under tension and consistently produces a measurement smaller than the actual finger circumference. For any measurement that will be used to craft a ring, particularly a full eternity band or a design that cannot be easily resized, TJ Diamond strongly recommends coming into our Auckland studio for professional sizing using calibrated metal sizing rings. Q4: Why do fingers change size throughout the day? Finger size fluctuates with temperature, time of day, recent exercise, fluid intake, and in some individuals, hormonal cycles. Fingers are typically at their smallest in the morning and at their largest in the evening, because warmth and circulatory activity throughout the day cause soft tissue to expand slightly. Cold temperatures cause fingers to contract; warm temperatures cause them to expand. The difference between a morning and evening measurement on the same finger can be up to one full ring size. For a consistent result, TJ Diamond recommends measuring in the evening at normal room temperature, ideally after light activity. Q5: Does ring width affect ring size? Yes, and this is one of the most commonly overlooked sizing factors. A wider band compresses more of the finger's surface than a narrow band, and as a result feels tighter at the same nominal size. A 7mm wedding band sized the same as a 2mm engagement ring band will feel noticeably tighter in wear. As a general guide, if you are ordering a band wider than 4mm, consider going up half a size from your standard measurement. TJ Diamond's jewellers account for band width in the sizing recommendation during Auckland studio appointments — this adjustment is not captured by circumference measurements alone. Q6: What happens if my ring does not fit after delivery? Plain gold and platinum bands can typically be resized up or down one to two sizes by a skilled jeweller without affecting the ring's integrity. TJ Diamond's lifetime warranty includes one complimentary resize within the first 12 months of purchase for any ring we make. Rings with diamonds set around the full circumference — full eternity bands, full pave rings — cannot be conventionally resized because the stone settings run through the section that would be added or removed. Channel-set and heavily embellished rings are more complex to resize than plain bands. For these styles, accurate pre-order sizing is essential. Q7: How do I find my ring size if I want to propose as a surprise? Several approaches work for a surprise proposal. If your partner owns a ring they wear on the ring finger of their left hand (the most common engagement ring finger), borrow it temporarily and trace the inner circle, then measure the diameter. Alternatively, ask a family member or close friend who may know the size. If no measurement is possible, the most common NZ women's engagement ring size is N (approximately US 6.75), but this is only an average. TJ Diamond recommends ordering a surprise engagement ring in a plain solitaire setting or a half-set design that can be resized, and bringing your partner in after the proposal for accurate sizing before the final ring style is confirmed. Q8: Is my ring finger the same size on both hands? Almost never. The ring finger on the left hand and the ring finger on the right hand are typically different sizes — often by half a size or more. This occurs because most people have a dominant hand that is slightly more developed through daily use, and dominant-hand fingers are often marginally larger. Always measure the specific finger on the specific hand the ring will be worn on. Do not assume that a size taken from your right ring finger applies to your left ring finger, or vice versa. If you are ordering a ring intended for the left hand, measure the left ring finger specifically.  

The bow-tie effect is a shadow pattern visible across the widest central section of certain elongated diamond shapes most commonly oval, pear, and marquise cuts. It appears as a dark horizontal area in the shape of a bow tie, running across the stone's midsection. In a well-cut diamond, it is subtle and adds depth. In a poorly cut stone, it is a dominant dark shadow that significantly detracts from the ring's visual appeal. The bow-tie effect does not appear on any GIA or IGI certificate. It cannot be assessed from photographs. It must be seen in person. This is the most important quality consideration for any elongated brilliant diamond, and the primary reason TJ Diamond assesses every oval, pear, and marquise diamond individually before setting. A diamond can carry a GIA Excellent certificate and a pronounced bow-tie shadow. The certificate does not disclose it. A product photograph will not show it. You need to see the stone in person. Why the Bow-Tie Happens In a round brilliant, the circular outline creates a symmetric facet arrangement where light entering from any direction is returned roughly equally from all parts of the stone. In an elongated shape oval, pear, marquise  the central facets are oriented differently from the facets at the rounded ends or pointed tips. In the central section, light reflecting off the pavilion facets exits through the sides of the stone rather than returning through the table to the observer's eye. This creates the characteristic dark shadow across the widest point. The size and intensity of the bow-tie depends on the diamond's specific pavilion facet angles in the central zone. A cutter who optimises the central angles can minimise the bow-tie. A cutter who maximises carat retention from the rough at the expense of proportional correctness produces a more pronounced shadow. Which Shapes Are Affected Oval diamond rings — the shape most significantly affected. The bow-tie falls directly across the most prominent visible area of the stone. See our oval engagement rings and our  oval diamond rings collections for our selection of individually assessed oval stones. Pear diamond rings — affected similarly to oval. The bow-tie typically appears lower in the stone, closer to the widest point. Wing symmetry significantly affects how evenly the shadow falls. See our pear engagement rings collection. Marquise diamond rings — both pointed tips converge, and the bow-tie appears across the widest central section. See our marquise engagement rings collection. Round brilliant, emerald, princess, radiant — not affected. Round brilliants have symmetric light return. Step-cut and princess/radiant facet arrangements do not produce this shadow pattern. Bow-Tie Severity — What Each Level Looks Like Severity What you see TJ Diamond stance None to minimal No visible shadow. Rare. Outstanding light return throughout. Select — exceptional quality Subtle Slight depth shadow in overhead light. Adds dimension. Considered desirable. Select — realistic optimum for most ovals Moderate Visible shadow in most conditions. Detracts from brilliance. Reject — below acceptable threshold Severe Dark butterfly immediately obvious. Dominates the stone. Reject — immediately apparent to all observers Why Photographs Cannot Show It Product photography uses a direct overhead light source — the exact condition that minimises bow-tie visibility. The same diamond that photographs brilliantly under studio lighting may display a pronounced shadow under the natural daylight or indoor lighting where it will actually be worn. Never assess an oval, pear, or marquise diamond from photographs alone. How to Assess It In Person View under multiple light sources. Move from direct overhead light to natural window light this reveals the real-world appearance. Tilt the stone side to side. A well-cut oval's bow-tie shifts with movement. A severe bow-tie maintains a fixed dark shadow regardless of angle. Compare two diamonds side by side. Bow-tie severity is much clearer in direct comparison than assessed in isolation. Ask whether the stone was individually assessed before purchase. TJ Diamond assesses every oval, pear, and marquise diamond for bow-tie severity at point of selection not from certificates. Is a Subtle Bow-Tie Desirable? Yes. A completely bow-tie-free oval is extremely rare and the cutting trade-offs required to achieve it often reduce other proportional qualities. Many experienced buyers and gemologists consider a subtle, well-contained bow-tie to add depth and dimension making the stone appear to have more internal volume than a completely flat-looking stone. The goal is not zero bow-tie. It is a bow-tie subtle enough to add depth without dominating the stone's appearance. TJ Diamond holds multiple oval and pear diamonds for side-by-side comparison at any studio consultation. Book a consultation to assess bow-tie in person. See our article on the best diamond cut for maximum sparkle for how the bow-tie fits into the wider picture of cut quality and light performance. Related: What is the best diamond cut for maximum sparkle? Frequently Asked Questions Q1: What is the bow-tie effect in a diamond? The bow-tie effect is a dark shadow pattern visible across the widest central section of certain fancy-shape diamonds — most commonly oval, pear, and marquise cuts. It appears as a dark horizontal area resembling a bow tie or butterfly shape, running across the stone's midsection and interrupting the diamond's brilliance in that region. The effect is caused by the optical geometry of elongated brilliant-cut diamonds, where light entering from above reflects off the central pavilion facets and exits through the sides of the stone rather than returning to the observer's eye. In a well-cut diamond, the bow-tie is subtle. In a poorly cut stone, it can be a dominant dark shadow. Q2: Does the bow-tie effect appear on a GIA or IGI certificate? No. The bow-tie effect does not appear on any GIA or IGI certificate. No diamond grading laboratory includes bow-tie severity in its grading reports because the effect is a viewing-condition-dependent optical characteristic rather than a measurable physical property of the stone. This means a diamond can have a pronounced bow-tie shadow and receive a GIA Excellent cut grade for its round dimensions (polish and symmetry) without the bow-tie being disclosed anywhere on the certificate. The bow-tie must be assessed visually, in person, under multiple light sources. This is one of the primary reasons TJ Diamond assesses every oval, pear, and marquise diamond individually before selection. Q3: Which diamond shapes are affected by the bow-tie effect? The bow-tie effect primarily affects elongated brilliant-cut diamond shapes: oval (most commonly and significantly affected), pear, and marquise. Elongated cushion cuts can also exhibit a similar shadow pattern in some cases. Shapes that are not affected include: round brilliant (symmetric light return from all directions prevents the shadow), emerald cut and Asscher cut (step-cut facets produce a different reflective pattern), princess cut (square brilliant facet arrangement does not produce the elongated shadow), and radiant cut (trimmed corners allow more even light distribution than strict elliptical outlines). Q4: Is some bow-tie effect desirable? Yes — a subtle bow-tie is considered desirable by many experienced diamond buyers and gemologists. A completely bow-tie-free oval diamond is technically possible but extremely rare, and the cutting required to achieve it typically involves trade-offs in other proportional qualities. A subtle, well-contained bow-tie creates an impression of depth and dimension, making the stone appear to have more internal volume than a completely flat-looking stone without any shadow contrast. The target for a well-cut oval, pear, or marquise diamond is not zero bow-tie — it is a bow-tie subtle enough to add depth without dominating the stone's appearance. TJ Diamond rejects diamonds with moderate or severe bow-ties, but selects those with subtle bow-tie depth. Q5: Can you see the bow-tie effect in product photographs? No — product photography almost always hides the bow-tie effect. Diamond ring photography uses a direct overhead light source positioned to maximise sparkle for the image. This specific lighting condition is precisely the one that minimises the bow-tie's visibility, because the overhead light directly illuminates the central facets that would otherwise be in shadow. A diamond can photograph as brilliantly sparkly under studio lighting and display a pronounced dark shadow under the office lighting or natural daylight where it will actually be worn. This is why viewing any oval, pear, or marquise diamond in person under multiple light conditions is essential before purchasing. Q6: How do I assess the bow-tie effect when buying an oval diamond ring? Three steps: First, view the diamond under multiple light sources — direct overhead light minimises the bow-tie; move the stone toward a window or under diffuse ambient light to see its real-world appearance. Second, tilt the stone slowly from side to side — a well-cut oval's bow-tie should shift and change as the stone moves, indicating good overall light return. A severe bow-tie maintains a fixed dark shadow regardless of movement. Third, compare two diamonds side by side under the same conditions — bow-tie severity is much easier to assess relatively than in isolation. TJ Diamond holds multiple oval and pear diamonds for comparison during Auckland studio consultations. Q7: Do oval diamond rings always have a bow-tie effect? Almost all oval diamonds have some degree of bow-tie effect — it is an optical characteristic inherent to the elongated brilliant cut geometry rather than a cutting flaw. The question is severity, not presence. The range runs from imperceptible (a very slight depth shadow that most observers would not notice and that adds dimension) to severe (a dark butterfly shadow immediately visible to any observer that significantly reduces the ring's visual appeal). TJ Diamond's selection process rejects stones with moderate or severe bow-ties and selects stones where the bow-tie is subtle or minimal. Our Auckland jewellers assess this for every oval, pear, and marquise diamond before it enters our workshop. Q8: Does the bow-tie affect an oval diamond's price? The bow-tie effect is not graded and does not appear on certificates, so it does not directly affect the wholesale price of a diamond. However, a well-cut oval with a minimal bow-tie commands a premium in the fine jewellery market because experienced buyers and jewellers know the quality difference. At TJ Diamond, we source ovals specifically for cut quality and bow-tie assessment — this means our selection skews toward better-cut stones, and our prices reflect the quality of the selection process rather than raw certificate grades alone. A cheaper oval diamond from a less selective source may have a more pronounced bow-tie at the same certificate grades.    

An eternity ring is a band set with diamonds running either fully around the circumference or along the top half only. The unbroken circuit of stones no beginning, no end is both the design and the meaning: an enduring love, a lasting commitment, a milestone that has no natural stopping point. At TJ Diamond, eternity rings are among our most requested commissions after engagement rings. Full Eternity vs Half Eternity — The Decision That Matters Most Full eternity ring: Diamonds set continuously around the entire band. The most visually impressive configuration. Cannot be conventionally resized after setting accurate sizing before ordering is essential. Half eternity ring: Diamonds set along the top half only, with plain metal on the underside. Can be resized one to two sizes. From the front, indistinguishable from a full eternity in most viewing conditions. If you are ordering as a surprise gift, choose a half eternity. The plain metal underside allows conventional resizing after the ring is received. A full eternity ordered in the wrong size cannot be easily corrected. Setting Styles for Eternity Rings Channel setting: Each diamond held between two parallel metal rails. Smooth, flush, snag-free. The best daily-wear configuration. Most popular for eternity wedding bands. Prong setting: Each diamond held by individual claws. More light reaches the stone higher sparkle. Requires annual prong inspection. TJ Diamond lifetime warranty covers this at no charge. Pave setting: Very small diamonds set closely together with tiny metal beads. A continuous river of sparkle. Most luxurious appearance. Requires careful wear and regular inspection. Diamond Shapes in Eternity Rings Round brilliant diamonds — tile evenly around any band width for a seamless, gapless circuit of sparkle. See our full round engagement rings collection for our available round stone specifications. Princess cut diamonds — square outline tiles as cleanly as round. Geometric and contemporary character. Emerald cut eternity bands — three rectangular step-cut stones side by side create a striking architectural band. A deeply sophisticated alternative to brilliant cuts. When to Give an Eternity Ring Milestone anniversary — 5, 10, 20, 25, or 50 years. The most traditional occasion. The unbroken diamond circuit references the duration of the relationship. Birth of a first child. A circle of diamonds referencing new beginnings. A narrow pave eternity in rose gold is among our most popular configurations for this occasion. As a wedding band alongside an engagement ring — a full or half eternity creates a deeply impressive bridal combination. See our full wedding bands collection for all band styles. Milestone birthday or self-purchase. The unbroken circuit carries personal meaning equally well — a significant life chapter, an achievement, a new beginning. Metal Choice for Eternity Rings Platinum: platinum engagement rings never needs replating, work-hardens rather than eroding, most hypoallergenic. The most popular eternity ring metal at TJ Diamond. The dimensional integrity of the band setting is best preserved over decades in platinum. Yellow gold: yellow gold engagement rings also never needs replating. Provides the colour grade advantage (G-H colour diamonds appear as colourless in yellow gold). Strong return in popularity in NZ in 2024-25. Rose gold: warm, romantic, no replating required. Particularly popular for first-child eternity rings. Sizing — The Most Important Practical Note Full eternity rings cannot be conventionally resized. There is no plain metal section available for size adjustment. For full eternity rings, TJ Diamond takes the measurement in our Auckland studio using calibrated metal sizing rings, and accounts for band width  wider bands feel tighter and require a slightly larger size. For any uncertainty about sizing, choose a half eternity. Browse our full range of diamond wedding bands and eternity ring styles or contact us to discuss your eternity ring requirements and book a studio sizing appointment. Related: Engagement ring vs wedding ring Frequently Asked Questions   Q1: What is the difference between a full eternity ring and a half eternity ring? A full eternity ring has diamonds set continuously around the entire circumference of the band. A half eternity ring has diamonds set along approximately the top half only, with plain metal on the sides and underside. The most important practical difference is resizability: a half eternity can typically be resized one to two sizes because the plain metal sections allow conventional size adjustment. A full eternity cannot be conventionally resized after setting because the stone settings run through the section that would be added or removed. If you are ordering a full eternity ring, accurate sizing before the ring is made is essential. Q2: When is an eternity ring traditionally given? The most traditional occasion is a significant wedding anniversary — five years, ten years, twenty-five years, or fifty years. The unbroken circuit of diamonds references the duration of the relationship: no beginning, no end. Other increasingly common occasions in New Zealand include the birth of a first child, a milestone birthday, and as a wedding band alongside an engagement ring. There is no rule about when an eternity ring must be given. Any occasion that carries the meaning of enduring love or commitment is appropriate. Q3: Can an eternity ring be worn as a wedding band? Yes. An eternity ring worn as a wedding band at the ceremony is one of the most popular configurations at TJ Diamond. A full or half eternity in platinum or yellow gold worn beside or instead of a traditional plain band creates an impressive bridal combination. The most important consideration when wearing an eternity ring as a wedding band is that it must be sized precisely before ordering, because it cannot be easily resized after setting if it contains diamonds around the full circumference. Q4: What is the difference between a channel-set and prong-set eternity ring? In a channel-set eternity ring, each diamond is held between two parallel metal rails rather than by individual prongs. The result is a smooth, flush surface with no protruding elements — the most snag-free configuration for daily wear. In a prong-set eternity ring, each diamond has its own individual claws, typically four per stone. More diamond surface is exposed to light in a prong-set ring, producing slightly more brilliance and scintillation. Prong-set eternity rings require periodic prong inspection — TJ Diamond recommends a professional check every 12 months. Our lifetime warranty covers this prong maintenance at no charge. Q5: Can a full eternity ring be resized? A full eternity ring cannot be conventionally resized after setting because the stone settings run continuously around the entire band — there is no plain metal section to add or remove for a size adjustment. If a full eternity ring is the wrong size, the options are limited to: wearing it on a different finger, having the stones reset into a new band of the correct size (significant cost), or in some cases adding small ring sizers to the inside of the shank. This is why precise pre-order sizing at TJ Diamond's Auckland studio is so important for full eternity rings. If you are ordering as a surprise gift, a half eternity is strongly recommended. Q6: What metal is best for an eternity ring? Platinum is the most popular metal for eternity rings at TJ Diamond for three reasons: it never needs replating (white gold requires rhodium replating every 1-3 years), it work-hardens rather than eroding with daily wear so the band retains its dimensional integrity over decades, and it is the most hypoallergenic precious metal available. Yellow gold is the second most popular choice — it also never needs replating, provides a colour grade advantage for the diamonds it holds (G and H colour stones appear as colourless in yellow gold), and has seen a significant return in popularity in New Zealand in 2024-25. Q7: How much does an eternity ring cost in NZ? Eternity rings at TJ Diamond start from $999 NZD for a diamond-set half eternity band. The total price depends on: the total diamond carat weight across all stones, the diamond quality (colour and clarity), the setting style (channel, prong, or pave), the metal (yellow gold, rose gold, or platinum), and whether the ring is a full or half eternity. Lab-grown diamonds make eternity rings significantly more accessible — the same visual impact with 50-70% less spend on the diamond content. Contact us for a personalised quote based on your specific eternity ring requirements. Q8: What diamond shape works best in an eternity ring? Round brilliant diamonds are the most popular and most practical choice for eternity rings. Their circular outline tiles evenly around the band at any width, producing a continuous, gapless circuit of sparkle. Princess cut diamonds also tile well due to their square outline. Emerald cut eternity rings are a beautiful option for buyers who want the step-cut architectural character in a band format — three emerald cuts side by side create a striking geometric composition. Oval, cushion, and pear shapes can be used in eternity bands but require more careful spacing and produce a slightly less seamless result than round or princess cuts.