Lab Grown Diamond Earrings: Sizes, Settings and What to Spend

Buy cut, save on everything else. That is the short version for lab grown diamond studs, and it is more true for earrings than for any other piece of jewellery, because nobody ever looks down through the table of an earring the way they look down through the table of a ring.

A ring is worn at chest height, held up, turned under a light, examined at twenty centimetres. An earring sits at the side of a head, viewed from an angle, usually in motion, usually at a metre or more, and half the time partly covered by hair. The angle you almost never see is straight down through the table, which is exactly the angle grading laboratories use and exactly the angle at which colour and clarity become visible.

So on an earring you can drop colour and clarity further than you would on an engagement ring, and put the money into cut and carat weight instead.

How carat weight is quoted, and the trap in it

Earrings are quoted in total carat weight, written as TCW or ctw, and it means the two stones added together. A one carat pair is two half carat stones. Not two one carat stones.

This is the single most expensive misunderstanding in the category. If you have been looking at one carat engagement rings and then see a one carat pair of studs at what looks like an incredible price, the price is not incredible. You are looking at half the stone in each ear.

Some sellers do quote per stone, particularly at the higher end. If a listing says "1ct" with no further qualification, assume total and confirm before paying. Diameter is the number that actually describes what someone will see, so use that rather than carat where you can.

The size table

For round brilliant cut stones, at standard proportions.

Total carat weight	Each stone	Approximate diameter per stone	How it reads
0.5ct total	0.25ct	About 4.1mm	Discreet. Visible, does not announce itself. A good everyday first pair
0.75ct total	0.375ct	About 4.6mm	Still everyday, noticeably more presence
1ct total	0.5ct	About 5.0mm	The most common pair sold. Reads clearly across a table, still fine at work
1.5ct total	0.75ct	About 5.8mm	Starting to be a feature rather than an accent
2ct total	1ct	About 6.4mm	Unmistakable. Roughly the width of a pencil
3ct total	1.5ct	About 7.4mm	Statement size. Weight starts to matter here
4ct total	2ct	About 8.1mm	Occasion earrings for most people

Two notes on reading that table. Fancy shapes at the same carat weight cover different amounts of surface area: ovals, pears and marquise cuts all look larger than a round of the same weight because they spread, and princess cuts look smaller face up than their weight suggests. And a poorly cut stone carries weight in the pavilion where nobody sees it, which is one more reason cut grade is not optional. If you want a physical reference before ordering, measure an existing pair with a ruler.

Which grades are invisible in an earring

Here is where the money is.

Cut. Do not compromise. Excellent or ideal, with polish and symmetry both good or better. Cut controls how the stone returns light, and light return is the entire visible effect of an earring at a metre. A poorly cut two carat pair looks duller than a well cut one carat pair. This is the one grade you can see from across a room.

Colour. Go lower than you would on a ring. On an engagement ring I would normally stop around G. On studs, H and I are safe in white gold and platinum, and in yellow or rose gold you can go further still because the metal warms the appearance anyway. Colour is judged face down against a white tray under controlled lighting, and an earring is never in that position.

Clarity. Go lower again. SI1 and SI2 are usually eye clean at earring viewing distance in a round brilliant, and even a stone with a visible inclusion at ten centimetres is unremarkable at a metre from the side. VS is comfortable. VVS is money spent on a certificate.

The one exception. An emerald or asscher cut has long, open, unbroken facets that hide nothing, so an inclusion that vanishes in a round brilliant will sit there visibly in a step cut. If you want step cut studs, move clarity up to VS2 or better and take the colour saving instead.

Every lab grown diamond we set is IGI certified and laser inscribed on the girdle with its report number, so you can match the stone to the paper yourself. If reading a report is new to you, what an IGI certificate actually tells you covers it, including checking the number on IGI's own database rather than trusting a screenshot.

Settings, and who each one suits

Four claw. Four prongs holding the stone, minimum metal, maximum light entering from the sides. The stone looks slightly larger because less of it is covered, and a round stone set in four claws reads faintly square from a distance, which some people like. The trade off is that four claws is three claws plus a problem if one lifts. Check them annually.

Six claw. More metal, more security, marginally less light from the side. The stone reads rounder. This is the sensible default for anything from about a carat each upward, because the consequence of a claw failing on a larger stone is proportionally worse.

Bezel. A continuous rim of metal around the girdle. This is the setting I recommend most often and the one people ask for least, because it covers a millimetre of stone edge and everyone wants maximum stone. What you get instead is a stud with no protruding metal at all.

That matters more than it sounds. Bezel set studs do not catch in hair, so if you have long hair they will not tug at it every time you pull a jumper over your head. They do not catch on a baby's grip, which anyone with small children will understand immediately. They do not snag on a scarf, safety glasses straps or hearing protection, so if you wear protective equipment at work, bezel is the setting that survives. The rim also protects the girdle, the thinnest and most chip prone part of a diamond.

Martini. A three claw setting where the claws form the basket, named for the cone shape. It sits very low and close to the lobe, uses the least metal of any of these, and is the lightest option at a given carat weight. Good for anyone who wants a larger stone without the weight, and good for a second or third piercing where clearance is tight. It is the least secure of the four, so if you are hard on jewellery, go elsewhere.

Backs, and the weight problem

Butterfly backs. The standard friction back: two hinged wings that grip the post. Cheap, fast, and they loosen over time as the metal fatigues. If yours slide off the post easily, they are done, and replacing them is inexpensive. Fine for smaller studs.

Screw backs. The post is threaded and the back screws down. Genuinely secure, and the correct answer for anything expensive or anything you sleep in. They are slower to fit, awkward with long nails, and the thread can cross if you rush it. Some sellers advertise "screw back" for a threaded post with a friction back, which is not the same thing. Ask whether the back itself is threaded.

La Pousette. A locking back with a spring loaded button you press to release. The most secure of the three, the easiest to operate one handed, and the most expensive. If you have arthritis, limited dexterity, or you have already lost one expensive earring, this is what to buy.

When weight starts to drag. A stud does not just hang, it levers. The stone sits in front of the lobe and its weight rotates the post forward, so the top of the post digs in and the lobe stretches over time. Most people are entirely fine to about one carat per stone. Between one and one and a half carats, setting choice starts to matter and a martini or light basket helps. Above roughly one and a half carats per stone, worn daily over years, lobes visibly stretch, and that is not reversible without surgery.

Two things reduce it. Choose the lightest setting that is secure enough, since basket weight is a meaningful share of stud weight. And use a back with a larger flat disc, sometimes sold as a lobe support, which spreads the load across more skin instead of concentrating it on the post.

Earrings have no sizing problem

This is why earrings are the easiest piece of fine jewellery to buy online, and it deserves saying plainly.

A ring has to fit. Fingers change size with heat, salt, exercise, pregnancy and time of day, which is why we send a free ring sizer before casting and why resizing exists at all. A bracelet has to fit. A necklace has a length you have to decide on.

An earring goes through a hole that is a standard size. Posts run around 0.8mm to 1mm in diameter and fit a standard piercing. There is no measurement to take, no sizer to post, no resize afterwards. The only variables are whether you want them and whether you like them, both of which you can settle from photographs and a video call.

That makes studs the lowest risk fine jewellery purchase there is, and a sensible first order from a jeweller you have not bought from before.

You can see the range on the earrings collection. If you are here because you are also looking at an engagement ring, lab grown diamond engagement rings is the other place to look, and if you want to talk through sizes with something physical in front of you, book an appointment in Melbourne or by video call.

What I would buy

For a first pair worn daily: one carat total, so half a carat each at about 5mm, excellent cut, H colour, SI1 clarity, six claw or bezel, screw backs. That combination looks like considerably more money than it is, and the grades you dropped are grades nobody can see at the distance the earrings are actually viewed.

For a larger pair worn daily: two carats total, so one carat each at about 6.4mm, excellent cut, bezel set for the protection, La Pousette backs. Stop there for daily wear unless you are willing to accept lobe stretch over the years.

For occasion earrings: go as large as you like, because a few hours at a time does not stretch anything, and use screw backs.

FAQ

Does 1 carat earrings mean one carat in each ear?

Usually not. Total carat weight is standard for earrings, so a one carat pair is two half carat stones of about 5mm each. If a listing does not say "each", assume total and confirm in writing before paying.

What clarity do I need for lab grown diamond studs?

SI1 or SI2 is usually eye clean at the distance an earring is actually viewed in a round brilliant, and VS is comfortable. Step cuts like emerald and asscher are the exception, because their open facets hide nothing, so move up to VS2 or better in those shapes.

Which earring back is most secure?

La Pousette locking backs, then screw backs, then butterfly friction backs. For anything expensive or anything you sleep in, do not use butterfly backs.

What size studs look best for everyday wear?

Between 4mm and 5mm per stone, which is 0.5ct to 1ct total. That range is visible across a table, appropriate at work, and light enough that the lobe does not stretch over the years.

Can heavy earrings stretch your ears?

Yes, over years of daily wear. Most people are fine to about one carat per stone. Above roughly one and a half carats per stone worn daily, stretching is common and it does not reverse on its own. Lighter settings and larger flat disc backs both reduce the load.

Are lab grown diamond earrings a good first online jewellery purchase?

They are the best one, because there is nothing to size. Posts and piercings are standard, so unlike a ring or a bracelet there is no fit to get wrong and no resize afterwards.