The stone
The parts of a diamond, and how it's cut.
- Table
The big flat facet on the very top of the stone, and the one you look down through. Everything you see when you look at a ring comes back up through it, which is why a flaw sitting dead center under the table is the one you'd eventually notice and a flaw out at the edge disappears under a prong.
Also: the furniture, and a grid of rows on a page.
- Crown
The top of the stone, everything above the widest line. It's the part that faces up out of the ring, so it's the part she and everyone else actually sees.
Also: what a king wears, and the top of a tooth.
- Pavilion
The cone-shaped bottom half, below the widest line, hidden down inside the setting. How deep it runs decides whether light bounces back out the top at you or leaks out the bottom, which is most of what a cut grade is measuring.
Also: a tent or a garden building.
- Girdle
The thin band around the stone's widest edge, where the top half meets the bottom. Many certified stones carry the report number laser-inscribed on it, so it's the line to ask a jeweler to put under the microscope.
Also: the undergarment.
- Culet
The tiny facet at the very bottom, right at the tip. Aim for None or Very Small on the report, because anything larger can show as a dark dot under the table.
Say it: KYOO-let.
- Facet
One of the flat polished faces cut into a stone. A round brilliant has 58 of them, angled so light coming in the top bounces around inside and comes back out at you.
- Depth
How tall the stone is from top to bottom, given on the report as a percentage of how wide it is. On a round you want roughly 59 to 63 percent, and much deeper than that means paying for weight buried in its belly that nobody can see.
Also: the ordinary word, as in covering something in depth.
- Polish
A grade on the report for how finely the facets were finished, running Excellent down to Poor. On a round with an Excellent cut grade it's usually along for the ride, and on any other shape it's one of the two grades to hold out for at Excellent, because GIA gives those shapes no cut grade.
Also: the ordinary verb. A jeweler polishing a scratch out of a band is doing something else.
- Symmetry
A grade on the report for how precisely the facets line up with each other, also Excellent down to Poor. It's the other half of the pair to hold out for on any shape that isn't a round.
Also: the ordinary word for things being evenly matched.
- Brilliant cut
A cutting style with triangular and kite-shaped facets arranged to throw light straight back at you. The round brilliant is the one you'll meet most, and when any shape is described as brilliant-cut, sparkle is what it's built for.
Also: "brilliant" on its own is just the ordinary adjective.
- Step cut
A cutting style with long flat facets in parallel rows, like steps, giving broad clean flashes instead of fireworks. The emerald cut and the Asscher are the two you'll meet, and both show flaws more readily than a brilliant does, so that's where you spend the clarity grade.
- Fancy shape
Any diamond shape that isn't a round. GIA gives none of them a cut grade, so on a GIA report you judge them on Polish and Symmetry instead, and they usually cost less per carat than a round of the same grades.
Also: fancy here means "not round." It doesn't mean fancier or more expensive, and usually it's the opposite.
- Face up
Looking straight down at the stone the way it sits on her hand. It's how a diamond gets judged, photographed and compared, and it's why two stones of the same weight can look like different sizes.
Shapes
The round brilliant and every fancy shape.
Every shape we recommend is on the 4Cs page.
- Round brilliant
The classic round diamond, and the reference point for everything else. It's the only shape GIA gives a cut grade to, and it costs the most per carat, which is why every other shape is a way of buying more stone.
- Oval
An elongated round that sparkles nearly as hard and looks larger than a round of the same weight.
- Princess
A square with sharp corners and serious sparkle, often priced lower per carat than a round.
- Cushion
A pillow-soft square with big facets and a vintage warmth, descended from the old mine cut.
- Emerald cut
A rectangular step cut with long, elegant lines that shows off clarity more than sparkle.
Also: emerald, the green gemstone.
- Radiant
The outline of an emerald cut with the facets of a brilliant, so it throws light like a round inside a rectangle.
- Pear
A teardrop shape, and like the oval it makes her finger look longer.
- Marquise
Long and narrow with pointed ends, and the largest face-up area of any shape, so it looks bigger for its weight.
- Asscher
A square step cut with cropped corners, named after the family who cut the first one. Like the emerald cut it shows flaws more readily than a brilliant does, so buy the clarity.
Say it: ASH-er.
- Heart
The romantic's shape and the least forgiving one, since it needs a skilled cutter and enough size for the shape to read.
- Old mine cut
An antique cut from before electric light, made to glow under candles rather than flash under spotlights. GIA doesn't give it a cut grade, so this is the one shape where you're buying a stone's history rather than its grades. You'll meet its round cousin under the name European cut.
- Bow tie
A dark band shaped like a bow tie across the middle of an oval, pear or marquise, caused by the way those shapes bend light. Some barely show it and some can't hide it, so watch the video before you buy.
The grades
The 4Cs and the grades a report prints.
- 4Cs
Cut, color, clarity and carat, the four measures every diamond is priced by. They don't matter equally: cut makes the sparkle and is the one never to trade down, and the other three are where the savings are.
- Cut grade
How well the stone was cut, which is what decides whether it sparkles. GIA grades it on round stones only, so on a GIA report a fancy shape arrives without one.
- Excellent and Ideal
The top of the cut scale, under two names. GIA's best grade is Excellent and IGI's best is Ideal. Hold out for the top word on whichever report you're handed.
- Very Good, Good, Fair, Poor
The rest of the cut scale below the top grade. Very Good is the one you'll be offered as close enough, and the answer is still the top grade; Fair and Poor visibly kill the sparkle, and nothing else on the report makes up for it.
- Color grade
How little color the stone has, graded D through Z. The scale runs backwards with D at the top, and there's no A, B or C to climb toward.
- Colorless and Near Colorless
The top two bands: D to F is Colorless, G to J is Near Colorless. G and H look icy white on a hand and cost well below the D to F grades nobody can tell apart.
- Faint, Very Light, Light
The bottom of the color scale, K through Z, where the warmth starts to show. A warmer stone reads whiter set in yellow or rose gold than it does in white metal, which is why the metal and the color grade are really one decision.
- Clarity grade
How few natural marks the stone has, on an eleven-step scale from FL at the top down to I3. The codes are abbreviations rather than ranks: VS is very slightly included and SI is slightly included, so once you know that the order stops being arbitrary. Face up, everything from FL down to VS2 looks the same.
The ladder, top to bottom: FL, IF, VVS1, VVS2, VS1, VS2, SI1, SI2, I1, I2, I3. VS2 and better read eye-clean almost every time. SI1 sometimes does and sometimes doesn't, so look before you buy. SI2 is where the marks stop hiding, and from I1 down they show without any help.
- Fluorescence
How much the stone glows under UV light, reported as None, Faint, Medium, Strong or Very Strong. It gets described and never graded, so nothing on this line is a pass or a fail. A small number of Strong and Very Strong stones read slightly hazy in direct sun, so with either word on the line, look at the stone outdoors or in the video before you commit.
- Eye-clean
No flaws you can see without magnification, which is the only clarity question that matters on a hand. It isn't a grade and it isn't printed on the report, so it's a judgment you make from the video or by asking, and VS2 and better gets you there almost every time.
- Inclusion
A natural mark inside the stone, formed while it grew. Almost every diamond has some, and clarity grades how many there are, how big, and how easy they are to find.
Also: the ordinary word.
- Blemish
A mark on the outside of the stone rather than inside it, like a scratch or a nick left from cutting. Blemishes count toward the clarity grade too, and a polish grade of Excellent means there are few of them.
- Clarity plot
The little map of the stone on the report showing where its marks sit. It answers what the grade can't: a feather out near the girdle disappears under a prong forever, and the same feather dead center under the table is the one you'd spot at brunch. The symbols on it, crystal and feather and cloud and pinpoint, are just the shapes of the marks.
- Carat
How much the stone weighs, and nothing about how big it looks. It's how a diamond is priced, and prices jump at the round weights, which is why buying just under one gets you a stone that looks the same for noticeably less.
- Karat
Gold purity, the k in 14k and 18k. Same sound as carat, completely different job: you're buying a one carat stone in a 14k band. The higher the number the more gold and the softer the metal, which is why rings are made from 14k and 18k rather than pure gold.
- Carat total weight
The combined weight of every diamond on the ring, the center stone and all the small ones added together. Two rings can both read 2.00 ctw and sit thousands apart, so the question to ask is what the center stone weighs on its own.
- Center stone
The main diamond, the one everything else on the ring is arranged around. When a seller quotes a total weight, this is the number to ask for on its own.
- Price per carat
What the stone costs divided by what it weighs, which is how the trade compares two stones that aren't the same size. A round costs the most per carat and every fancy shape usually costs less, which is most of the reason to consider one.
The paperwork
The grading report, and the papers that pass for one.
- Grading report
The document an independent lab writes about one specific stone: its grades, its measurements and its map. It's the thing you're buying alongside the diamond, because without it every grade is just what the seller told you.
- Certificate
What most people call the grading report, and what you'll hear at a counter. Watch where the word comes from: an independent lab issues a report, and a store handing you its own certificate has graded its own homework.
- Report number
The stone's ID in the lab's records, printed on the report and often laser-inscribed on the girdle. Type it into the lab's own lookup and the lab's copy comes up, so you can hold it against the seller's listing.
- Report Check
GIA's free lookup: you type the report number in and the lab shows you its own copy of the grades. It takes thirty seconds and it proves the paper is real; matching the stone to the paper is the laser inscription's job.
- Laser inscription
The report number etched onto the stone's girdle, far too small to see with the naked eye. Ask the jeweler to show it to you under magnification and you've matched the stone in front of you to the paperwork in your hand.
- Diamond Dossier
A shorter GIA report for smaller stones: the same grading, no clarity plot, and the report number always laser-inscribed. If you're handed one instead of the full report, it's a real GIA document rather than a downgrade.
- The labs
GIA and IGI are the two labs whose reports we'd accept, and GIA is the one to ask for when you have the choice. AGS was a third until it closed in 2022 and merged into GIA, so an older AGS report is legitimate, and any other name on the paper is a reason to slow down.
- In-house cert
A grading document a store writes about its own stones. It isn't independent and it isn't a lab report whatever the paper looks like, which is why the rule stays GIA or IGI.
- Appraisal
A document putting a replacement price on the finished ring, usually written by the jeweler who sold it to you. It's what your insurer prices the policy from, and it can't stand in for the lab's grading report, because valuing a ring and grading a stone are different jobs.
- Appraised value
The number on the appraisal: what it would cost to replace the ring at retail today. It isn't what you paid and it isn't what a resale would fetch, so don't read it as cash the ring is worth.
See also: rider.
Settings and metals
How the ring holds the stone, and what it's made of.
Every setting style we cover, with a picture of each, is on the metal and setting page.
- Setting
The ring your stone sits in: the band, the metal that grips the stone, and everything that isn't the diamond. A jeweler may call it a mounting, and it's the same thing.
Also: setting a date, setting money aside.
- Head
The metal at the top of the ring that grips the stone: the prongs and the frame they sit in. A tall head lifts the stone up off the band, and a lower one slides under a glove more easily.
Also: the ordinary word.
- Prong
One of the small metal claws that hold the stone in place, usually four or six of them. They wear down over years, so a jeweler checking them now and then is the maintenance that keeps the stone in the ring.
- Shank
The band, the part that goes around her finger. On a split-shank ring it divides as it nears the stone and joins again underneath.
- Solitaire
A single stone on a clean band, with nothing else competing for attention.
- Halo
A ring of tiny diamonds circling the center stone. It makes the center look up to half a carat larger, the most look per dollar of any setting we cover. A hidden halo tucks the small stones under the center instead, so it shows from the side and adds sparkle rather than size.
- Three-stone
A center stone with a smaller stone on each side, traditionally read as past, present and future.
- Pavé
Tiny diamonds set close together across the band so the metal nearly disappears. It's French for "paved," and that's what it looks like.
Say it: pah-VAY.
- Channel-set
Small diamonds tucked into a smooth channel along the band, with no prongs to snag on a glove or a sweater.
- Bezel
A rim of metal wrapped all the way around the stone instead of prongs. It's the most protective setting there is, which is why it's the answer for a shape with a sharp point and for hands that take a beating.
- Cathedral
Arches of metal rise from the band to hold the stone up, the way a cathedral lifts a ceiling.
- Basket
The stone sits down inside a cradle of metal, so it wears lower and slides under a glove.
- Trellis
Prongs that cross underneath the stone like woven branches, so the head looks grown out of the band.
- Split-shank
The band parts as it nears the stone and joins again underneath, which makes the center look larger.
- Bar
Straight bars of metal hold each stone, with the sides left open to let the light in.
- Flush
Stones sunk into the metal so nothing stands above the surface to catch.
- Tension
The stone held by the spring pressure of the band alone, touching metal at just two edges.
- Cluster
Many small stones arranged to read as one large one.
- East-west
The stone turned on its side so it lies across the finger instead of along it.
- Two-stone
Two stones side by side, often in different shapes.
- Infinity twist
A band that splits and winds around itself before it reaches the stone.
- Milgrain
A row of tiny metal beads along an edge, the detail that makes a ring read as vintage. It's decoration rather than structure, so you're buying a look, and it protects nothing.
- Platinum
A naturally white metal that never needs plating, dense enough to grip a stone securely and gentle on sensitive skin.
- Yellow gold
The classic warm gold, which lets a warmer color grade read white.
- White gold
Gold alloyed pale and then plated with rhodium to make it bright white. The plating wears, so a white gold ring needs re-dipping every so often to look new, and that doesn't stop.
- Rose gold
Gold with copper in the alloy, which gives it a permanent pink color and makes it tough.
- Palladium
A naturally white metal like platinum and lighter on the hand, though fewer jewelers work with it, which complicates resizing later.
Origin
Where a diamond comes from, and the stones that only look like one.
- Lab-grown diamond
A real diamond, grown in a machine instead of dug out of the ground. Same carbon, same crystal, same hardness, graded on the same scales, and the report and the girdle inscription are the only places the origin shows.
The line people get wrong: a lab-grown diamond is a diamond. A simulant only looks like one.
- Natural diamond
A diamond that formed in the earth and was mined out of it. Natural says where a stone came from and nothing about whether it's a real diamond, because a lab-grown one is a real diamond too.
- HPHT
High pressure, high temperature, one of the two ways a lab grows a diamond, by squeezing and heating a seed the way the earth does. The same four letters mean something else on a natural stone's report, where they name a treatment applied after the fact, so check which one the paperwork means.
- CVD
Chemical vapor deposition, the other way a lab grows a diamond, built up layer by layer in a carbon-rich gas chamber. Either method gives you the same stone, so it's a fact about the machine rather than about what you're buying.
- Simulant
A stone that looks like a diamond and is a different material underneath. Moissanite is the one a jeweler will actually offer you, and cubic zirconia is the one behind a price that looks impossible.
The line people get wrong: a lab-grown diamond is a diamond. A simulant only looks like one.
- Moissanite
A stone in its own right, so don't think of it as a cheap diamond. It's lab-made, tough enough for daily wear, and it throws more rainbow flash than a diamond does, which is how people pick it out.
The line people get wrong: a lab-grown diamond is a diamond. A simulant only looks like one.
- Cubic zirconia
A cheap man-made stone that looks like a diamond from across a room and isn't one. If a price looks impossible for the size, this is often why.
- Treated
A natural diamond improved for clarity or color after it came out of the ground. The report says so, and the seller has to tell you.
- Kimberley Process
The international scheme set up to keep conflict diamonds out of the legitimate trade, by making every rough-diamond export carry a certificate saying the stones are conflict-free. It doesn't certify jewelers, so ask the store you buy from how they know your stone isn't a conflict diamond, and ask to see their policy on it.
See also: conflict-free.
- Conflict-free
The promise that a diamond didn't pay for a rebel war against a government, which is what a Kimberley Process certificate says about a shipment of rough stones. A lab-grown diamond is conflict-free by definition, because no mine was involved, and on a natural one it's the store's own claim, so ask how they know.
See also: Kimberley Process.
Buying
Timing, returns, resizing, deposits and insurance.
- Virtual inventory
Diamonds a seller lists and will sell you, but doesn't have in the building. They sit with wholesalers until someone buys one, which is why "when can I actually have it" is a real question rather than a formality.
- Lead time
The gap between placing an order and holding the thing. It's what sets your order date rather than your decision date, which is why a plan counts backward from the day instead of forward from now.
- Bench jeweler
The person who actually works the metal, at a bench with a torch and a loupe, as opposed to the person who sells you the ring. Resizing, setting a stone and tightening a prong are all bench work, so it's worth knowing whether a store has its own bench.
- Loupe
The small 10x magnifier a jeweler holds up to his eye. Clarity is graded at 10x, so a flaw that only shows through a loupe is a flaw nobody looking at her hand will ever see.
- Return window
The days you have to send the ring back for a refund. Get the terms in writing before you pay, and ask whether engraving or a custom setting puts you outside it, because those are the usual exclusions.
- Resize
Having a jeweler cut the band and make it bigger or smaller. A band thins a little with each cut, so two or three over a ring's life is the practical limit, and sizing beads are the smaller fix that adds grip without cutting.
- Resize window
The set time after you buy when many jewelers will resize the ring free, and work by another jeweler can void the warranty. Ask what the window is and when the clock starts, and get it in writing, because a ring bought two months early can spend most of that window in a drawer.
- Rider
An add-on to your homeowners or renters policy that covers the ring specifically, for a set amount. Your policy already covers jewelry, but usually with a low cap on theft and often nothing at all for a ring you simply lose.
What to ask for: say you want to schedule an engagement ring on the policy. Then ask two things: what the jewelry limit is without it, and whether it covers loss or only theft and damage.
- Conversion clause
The line in a deposit agreement that turns your money into store credit if you pass on the stone. Get the terms in writing before you put anything down: the deposit comes back in full to the card you paid with if you walk, minus only an agreed shipping fee, and that fee credits toward the ring if you buy.
- Stock setting
A setting the maker already produces, ordered and shipped rather than made for you. It's the fast path, weeks rather than the month-plus a custom setting takes, and it's what makes a tight deadline possible.
- Resale value
What the ring would fetch if you sold it, which is not the same number as what you paid or what the appraisal says. It's one of the ways lab-grown and natural stones differ, and it's the number that matters least if you're keeping the ring.
Colored stones
Which colored stones hold up to daily wear.
- Mohs scale
The 1 to 10 scale for how well a stone resists scratching, with diamond at the top. For a ring she wears every day you want 7.5 or higher, which is what rules most colored stones out as a center stone.
- Sapphire
A hard gemstone best known in velvety blue, also found in pink, yellow and green, and a worry-free pick for an everyday ring.
- Ruby
A fiery red gemstone, and with sapphire the other worry-free pick.
- Emerald
A deep green gemstone, beautiful and workable in a ring if a protective bezel setting guards it.
Also: the emerald cut, a diamond shape.
- Morganite
A pink-to-peach gemstone that, like emerald, is workable in a ring with a protective bezel setting.
- Amethyst
A purple gemstone that sits just under the hardness floor for everyday wear, so it picks up scratches.
- Opal
A gemstone known for its play of color, and one that can crack with temperature swings, so it isn't a daily-wear stone.
- Pearl
A luminous gem so delicate that ordinary dust scratches it, which rules it out for an engagement ring.