What is the most important term to understand in this diamond glossary?

Cut. Of the 4Cs, cut quality drives visible sparkle more than any other grade, and it is the one most South African buyers under-weight. A 1 carat G VS1 with a poor cut can look duller than a well-cut H VS2. Insist on GIA Excellent cut at 1 carat and above.

Does a higher per-carat price mean a better diamond?

No, and the opposite trap is worse. Spec drives price far more than carat alone. Take the published benchmark: the Rapaport round list of 20 March 2026 prices G/VS1 at 1.00 to 1.49 carats at 5,400 US dollars per carat, so one loose carat works out at roughly R72,000 to R92,000 including VAT at R16.50 to the dollar, depending on the discount off list. A certified carat finished into a ring at a premium South African showroom ran R105,000 to R428,000 in my July 2026 listing work, with the setting inside that figure and only three listings of three different specifications behind the band. A low per-carat number is usually a lower grade rather than a bargain. Of 230 GIA-certified stones listed by six South African sellers in June 2026, only about 9 percent of the retail-held stock reached D to G colour with VS2 clarity or better. Read any sticker as a spec, not just a weight.

Is a lab-grown diamond worth less than a natural one?

On resale, yes, though the phrase near zero overstates it and this glossary would rather be precise. Lab-grown prices have fallen very steeply and are still falling, with published estimates of the decline running from roughly 70 percent to as much as 96 percent depending on the base year and the size being measured. The secondhand market is thin, some jewellers will not buy lab-grown back at all, and published estimates put what a private seller recovers at around a fifth to two fifths of the purchase price. A natural stone carries provenance, rarity and an established secondary market behind it. The terms defined here are written for natural-diamond buying, and a lab-grown stone is better bought for what it is now than as a store of value.

What certification should a South African buyer insist on?

GIA. For any natural stone above R30,000, insist on a numbered GIA Diamond Grading Report and verify it yourself at gia.edu/report-check. GIA grades consistently. EGL runs looser, especially on colour, and IGI is best known for lab-grown work.

Diamond Glossary | Natural Diamond

Q: What does it mean when a seller sources rather than stocks a diamond?

That the stone is not theirs yet. A seller who stocks owns the polished diamond and can put it in your hand today. A seller who sources pulls it on demand from a much larger external catalogue once you commit, which is how most of the trade works and how an exact colour, clarity and make gets found at all. Neither is a mark of quality by itself. The distinction that actually decides your risk is whether the diamond is seen or unseen: whether somebody who knows stones examines it before it reaches you, whether you can inspect it before paying, and whose problem it is if it turns out wrong.

The short answer, before the definitions

Short answer: learn colour, clarity and cut before any other word here, and buy from a manufacturer, cutting house or dealer.

Those three letters, not the carat weight, decide what a stone is worth. Almost every expensive mistake in this market is a buyer comparing weights while the grades quietly move underneath.
Cheaper up the chain. A retail counter buys at manufacturer, cutting house or dealer level and then roughly doubles the price, about three times at a branded showroom, while the steps between trade levels run at 3 to 5 percent.
Better up the chain. The specification most people want is about five times more common there, 52 percent of trade-access stock against 9 percent of retail-held stock.
They do the bench work too. Setting, bespoke commissions, and every maintenance word defined below, re-tipping and resizing included, plus insurance valuations and buy-back. A counter without a workshop sends those jobs to a bench like theirs.

Use a shop counter when the date will not move, when finished rings on a hand are how you decide, or when the brand is part of the purchase. Nothing in this glossary argues with that. It only makes sure you know what the words on the invoice mean before you sign it.

How to use this diamond glossary

Nine percent. That is the share of retail-held South African stock that reached D to G colour with VS2 clarity or better when I listed 230 GIA-certified natural diamonds across six sellers in June 2026. Among sellers working with trade access it was 52 percent, roughly five times as much. That gap is not hidden anywhere clever. It is written on the ticket, in letters and numbers most buyers cannot read. This diamond glossary exists so you can read them before you spend.

It defines the 60-plus terms a South African buyer needs before any serious purchase: the 4Cs, the supply-chain tiers, GIA grading, the cutting and setting vocabulary, and the trade pricing terms that decide what you actually pay. Definitions reflect my own research and the 2026 South African inventory and price work behind this site, as of the update date. Where it helps, I anchor a term to a figure from that work rather than a textbook range, and where the data does not reach far enough to settle a question I say so instead of rounding it off. Terms are grouped by theme, and the deeper category guides are linked at the end. If you want the full pricing picture first, start with our South African diamond price index.

The 4Cs

The 4Cs at a glance

The 4Cs describe weight, cut quality, body colour, and inclusions. For visual performance, cut usually matters most.

Carat. The unit of weight for a diamond, equal to 0.2 grams (200 milligrams). Carat is the most important variable for visible size and the most influential single factor in the per-stone price. A 1.00 carat diamond is roughly 6.5 mm in diameter for a round brilliant cut.

Cut. The proportions, polish, and symmetry of a finished diamond. GIA grades cut on a 5-grade scale: Excellent, Very Good, Good, Fair, Poor. Cut is the most important variable for visual sparkle and (in our editorial view) the most under-appreciated of the 4Cs by SA buyers.

Colour. The body colour of the diamond, graded D (best, colourless) to Z (lowest, lightly tinted). For engagement rings, G colour is the sweet spot for visually-colourless value in white-metal settings; J or K is acceptable in yellow-gold settings (the warm metal masks tinted body colour).

Clarity. The quantity, size, and visibility of inclusions and blemishes in the stone. Graded Flawless (FL, best), Internally Flawless (IF), VVS1, VVS2, VS1, VS2, SI1, SI2, I1, I2, I3 (lowest). There is no SI3 on the GIA scale; it is an EGL/trade grade, so treat any “SI3” listing with caution. For engagement rings, VS1 to eye-clean SI1 is the recommended range.

GIA grading and certification

GIA. The Gemological Institute of America, the global gold standard for diamond grading. Founded 1931. GIA grades every stone using the 4Cs and issues a numbered Diamond Grading Report verifiable at gia.edu/report-check.

GIA Report. The numbered grading certificate issued by GIA, with the report number laser-inscribed on the stone’s girdle. SA buyers above R30,000 should insist on GIA reports for every stone.

GIA Diamond Origin Service. GIA’s optional provenance-traceability programme that records the country of mining origin alongside the stone’s 4Cs grades. Only cutting houses enrolled in the programme can offer it, and a small number of South African cutters are. Ask before assuming a locally cut stone carries origin documentation, because most do not.

AGS Ideal. A cut standard from the former American Gem Society Laboratories. AGS Laboratories closed at the end of 2022 and its grading was absorbed by GIA, so AGS Ideal is no longer a separate report; it survives only as an optional GIA digital supplement. Treat GIA Excellent as the working top cut grade.

EGL. European Gemological Laboratories, an alternative grading body. EGL grading is roughly 10 to 15 percent cheaper than GIA but runs looser, especially on colour. Increasingly distrusted by US and UK buyers. SA buyers above R30,000 should prefer GIA over EGL.

IGI. International Gemological Institute, commonly used for lab-grown diamond grading and Indian-trade certification. I do not rely on it for serious natural-diamond buying in South Africa; I prefer GIA for natural stones.

Excellent cut. The highest GIA cut grade. Indicates excellent proportions, polish, and symmetry. The recommended cut grade for engagement rings at 1 carat and above.

South African supply-chain tiers

De Beers Sightholder. One of around 70 to 80 globally-approved companies with multi-year direct rough supply contracts from De Beers Global Sightholder Sales. A small number of Sightholders run cutting operations in South Africa. Sightholder-cut polished commands roughly 3 to 5 percent premium over comparable OTC stones.

OTC trade (Open-market trade). Cutting houses and dealers that source rough on the secondary market without direct miner contracts. Most working SA cutters operate at this tier. It is also where the order-in model lives: many sellers at this layer do not hold the polished stone at all, they bring it in on demand from a far larger external catalogue and ship it once you pay. See Sightholder vs Beneficiation Customer vs OTC for how the three tiers compare on price and provenance.

Beneficiation Act 2007. South African Diamonds Act 56 of 1986, as amended by the Diamonds Amendment Act 29 of 2005 and the Diamonds Second Amendment Act 30 of 2005 (in force 1 July 2007), the legislative framework requiring a percentage of De Beers’ SA-mined rough to be cut and polished within South Africa. Supports SA cutting-industry sustainability and black economic empowerment.

SADPMR. South African Diamonds and Precious Metals Regulator. The statutory body that licenses every SA business handling diamonds, gold, or precious metals. Mandatory registration for any SA diamond supplier. Verify at sadpmr.co.za.

Diamond Dealers Club of South Africa. The SA trade body for diamond dealers and wholesalers. Member directory at diamonds.org.za.

Jewellery Council of South Africa. The SA trade body for retail jewellers and manufacturing jewellers. Member directory at jewellery.org.za.

Trade pricing terms

Rapaport price list. The diamond industry’s reference benchmark for wholesale pricing of GIA-graded polished diamonds. Published weekly via store.rapaport.com. Subscription $250 to $350 per year.

RAP minus. Trade convention for quoting wholesale prices as a discount off the Rapaport list. “RAP minus 30 percent” means a 30 percent discount off the current Rapaport list price for that exact spec. Worked through, so the arithmetic is visible: the round list of 20 March 2026 prices G/VS1 at 1.00 to 1.49 carats at $5,400 per carat, so one carat at Rap less 20 percent, converted at R16.50 to the dollar and grossed up by 15 percent VAT, is about R82,000 for the loose stone, with Rap less 10 percent at roughly R92,000 and Rap less 30 percent at roughly R72,000. Those are estimates on a published list, they move with the list, the rand and VAT, and they carry no setting.

RAP list. Same as Rapaport price list. Industry shorthand.

Wholesale. The trade-tier transaction between cutting houses or distributors and the retail jeweller. It is the level a retailer buys at before adding its own margin. Since the retail convention is keystone, roughly double the trade cost, the arithmetic implies wholesale sits somewhere near half a retail counter price for the same specification. That is a consequence of the convention rather than a rate I have measured, and the real gap on any given stone depends on what the seller paid and what it decided to charge.

Manufacturer-direct. Buying directly from the diamond cutting house rather than through a distributor or retail jeweller. It is the layer at which you can buy a stone the cutter actually made and still holds, one step below the retail counter in the chain. What it removes is structural rather than a discount somebody decided to grant you: trade convention is keystone, so the counter price is roughly double the trade cost and a branded showroom runs to about three times, while the margins between one trade level and the next are only about 3 to 5 percent a hop. What it does not do is guarantee the lowest number in front of you on any given day. A cutter carrying better goods can quite properly quote above a mall counter carrying worse, and comparing the two per-carat figures tells you nothing until the weight, colour, clarity, cut grade and laboratory are held still. See how wholesale diamond pricing works for the full stack.

Trade pricing. Pricing offered to credentialed jewellers and dealers rather than to the public. How far below a retail counter price it sits follows from the keystone convention described under Wholesale, not from any measured South African figure, because nobody publishes one. What can be derived is what the stone itself is worth: take the published round list for the bracket and grade, less the 10 to 30 percent the trade transacts under it, at R16.50 to the dollar plus 15 percent VAT, and a loose one carat round brilliant comes to roughly R71,500 to R92,000 in G/VS1, R60,000 to R77,000 in H/VS1 and R41,000 to R53,000 in I/SI1, all including VAT and all for the bare stone. See diamond price per carat South Africa for the same arithmetic from 0.30 to 3.00 carat.

Parcel pricing. Pricing for a batch (parcel) of stones bought together rather than per-stone. Buying a parcel is generally cheaper per stone than buying one at a time, because the seller moves slower goods alongside the desirable ones. No figure for that discount is published here, because parcels have not been measured for this site. What sets the ceiling on a parcel is the single-stone rate at the smallest bracket the published list reaches, 0.30 carat, where one loose round brilliant works out to about R5,000 to R6,500 including VAT in G/VS1, roughly R17,000 to R22,000 a carat against R71,500 to R92,000 a carat at a full carat. Melee in a parcel is smaller and cheaper per carat again, so treat that rate as an upper bound rather than a price.

Stone characteristics

Round brilliant. The most popular diamond cut, accounting for roughly 75 percent of all engagement-ring purchases worldwide. 57 to 58 facets (depending on culet) maximise light return for sparkle.

Fancy shape. Any non-round diamond cut. Includes oval, marquise, pear, emerald, asscher, cushion, princess, radiant, heart. Fancy shapes typically price 10 to 30 percent below round brilliants of the same colour and clarity.

Brilliant cut. Any cut with triangular and kite-shaped facets that maximise light return. Round brilliant, oval, marquise, pear, and heart are all brilliant cuts.

Step cut. Cuts with rectangular facets in steps. Emerald cut, asscher, and baguette are step cuts. Step cuts produce a hall-of-mirrors visual rather than sparkle. Inclusions show more in step cuts; insist on VS1-VS2 clarity.

Melee. Small diamonds, typically 0.05 to 0.20 carat each, used in tennis bracelets, halo settings, eternity bands, and pavé designs. Sold as parcels rather than individually certified.

Pavé. A setting style where small diamonds (melee) are set close together in metal so the surface appears paved with diamonds. Common in halo settings and eternity bands.

Solitaire. A single-stone setting. The most common engagement-ring style. Maximises focus on the centre stone.

Halo. A setting style with a centre stone surrounded by a ring of small diamonds (melee). Visually amplifies the centre stone (a 1.00 ct centre with halo reads like 1.30 to 1.50 ct).

Three-stone. A setting with three diamonds, traditionally representing past, present, and future. Centre stone larger; side stones typically half the centre’s carat weight.

Eternity band. A band with diamonds set continuously around the entire ring (full eternity) or partially (half eternity). Cannot be resized because the stones run continuously. Most-bought for wedding bands and milestone anniversaries.

Tennis bracelet. A flexible bracelet of identical or graduated diamonds set in a continuous line. Named after a US Open incident in the late 1970s, when a player stopped play to recover a lost diamond line bracelet. SA tennis bracelets typically use 50 stones at 0.05 to 0.20 carat each.

Tennis necklace. A continuous line of diamonds around the neckline, typically 16 to 22 inches. Standard 16-inch uses 80 to 150 stones. The highest-AOV SA category after large solitaire engagement rings.

Setting and metal terms

18ct white gold. Gold alloy at 75 percent gold purity (75/100 = 18/24 carat) with the remaining 25 percent silver, palladium, or other white-metal alloys. The SA default for engagement rings, wedding bands, and most jewellery.

Platinum. A naturally white precious metal. Roughly 60 percent more expensive than 18ct white gold at the same width. Heavier on the finger, holds prongs tighter, resists wear better.

9ct white gold. Gold alloy at 37.5 percent gold purity (9/24 = 37.5%). Cheaper than 18ct but discolours faster around prongs. Acceptable for non-stone-setting daily-wear jewellery; not recommended for engagement rings.

Setting. The metalwork that holds the diamond in the ring or other piece. Common types: prong, bezel, channel, pavé, tension.

Prong setting. Diamond held in place by 4 or 6 metal claws (prongs). Most common engagement-ring setting. Prongs need re-tipping every 5 to 10 years.

Bezel setting. Diamond fully surrounded by a metal rim. Most secure setting for daily wear. No prongs to re-tip.

Channel setting. Diamonds set in a continuous channel between two metal walls. Common for wedding bands and eternity bands.

Re-tipping. Re-securing the prongs of a setting to ensure the diamond is held tightly. Routine maintenance every 5 to 7 years for 18ct white gold and 7 to 10 for platinum.

Re-shanking. Rebuilding the back of the ring band where the metal thins from daily wear. Routine maintenance at year 15 to 20.

Compliance and origin

Kimberley Process (KPCS). The international agreement requiring rough diamond imports and exports to be accompanied by Kimberley Process certificates confirming conflict-free status. Mandatory under international law since 2003.

Kimberley Process certificate. The export-import document accompanying each rough-diamond shipment. SA suppliers participate via SADPMR registration. Verify supplier KP compliance through their SADPMR status.

RJC certified. Responsible Jewellery Council certification. A voluntary international chain-of-custody standard. Top-tier global jewellers require RJC from their suppliers.

Forevermark. De Beers’ branded-diamond pedigree programme. Forevermark diamonds are inscribed with a Forevermark identifier and come with provenance documentation. 5 to 15 percent premium.

Conflict-free. A diamond verified as not having funded armed conflict. The Kimberley Process is the international compliance framework. Reputable SA suppliers are KP-compliant via SADPMR registration.

Chain-of-custody. Documentary verification of the diamond’s path from rough-mining through cutting through retail. RJC certification is the highest non-Sightholder standard.

Lab-grown vs natural

Natural diamond. A diamond formed under heat and pressure in the earth’s mantle over millions of years. This is the only diamond category I recommend for serious jewellery on this site because it has rarity, provenance, and a stronger secondary market than factory-grown stones.

HPHT. High-Pressure High-Temperature, one of two main lab-grown diamond manufacturing methods. Mimics the natural formation conditions. Also used for colour-enhancement of lower-grade naturals.

CVD. Chemical Vapour Deposition, the other main lab-grown diamond manufacturing method. Grows the diamond layer-by-layer from carbon-rich gas. Most modern lab-grown comes from CVD.

Treatment. Processing applied to a diamond to improve its apparent grade. Common treatments: clarity-enhancement (laser drilling, fracture filling) and colour-enhancement (HPHT for naturals). GIA reports note any treatments. Treated diamonds typically not recommended for engagement rings.

Where to buy

Source vs stock. A real distinction, but not the one that decides what you are buying. A seller that stocks owns the polished stone and can put it in your hand today. A seller that sources pulls it on demand from a much larger external catalogue, which is most of the trade and is how an exact colour, clarity and make gets found at all. Neither is a mark of quality. The distinction that actually decides your risk is seen vs unseen: whether somebody who knows diamonds examines the stone before it reaches you, whether you can inspect it before paying, whether the report number matches the girdle inscription, and whose problem it is if the stone is wrong. Most diamonds sold online in South Africa are sourced and never opened here, and the sticker often looks cheaper because it leaves out VAT and import, or because the stone is a quiet downgrade on colour or clarity. How often an unseen stone disappoints is something I cannot put a number on, because nobody publishes it and a private buyer never sees the rejects. That is precisely why the question worth asking is who examined the diamond, when, and what happens if they were wrong.

Sandton. Johannesburg’s premium-jewellery hub, with a strong concentration of established boutique and specialist showrooms. This is retail, not manufacturing, so expect boutique mark-ups on stones that were usually cut elsewhere.

Manufacturer-direct. Buying from the cutting house that made the stone, usually by appointment, and the layer at which stock is genuinely held rather than pulled in from a catalogue. Because the retail doubling has not been applied yet, this is the level a retail counter itself buys at. What that means for your number depends on what the seller paid and what it chooses to charge, so treat it as a different position in the chain rather than a guaranteed discount.

Independent specialist. A South African jeweller, typically Sandton-based, operating independently of the chain-store networks. Useful for bespoke settings and one-off pieces. Verify whether they hold the centre stone or source it on demand before you compare prices.

Premium SA brand. A South African luxury jewellery brand running boutique-style retail, the likes of a premium showroom or a heritage jeweller. Strong on finishing and brand; you pay a boutique premium and the loose stone is usually sourced in.

Chain jeweller. A national jewellery chain trading from mall storefronts. Appropriate for sub-R30,000 entry-tier purchases. They rarely compete on loose natural stones at the R45,000-plus tier, where spec and provenance start to matter.

Budget local retail. The entry tier of the high street, and the source of the cheapest per-carat headlines a South African buyer will see. The headline is real. What it usually buys is a lower grade rather than the same diamond for less. The June 2026 listing behind this glossary counted 137 retail-held stones and 93 held by sellers working with trade access. D to G colour with VS2 clarity or better described 9 percent of the first group and 52 percent of the second. Cheap per carat is not cheap per quality.

Buyer-protection and verification

SADPMR registration. Mandatory licensing for any SA business handling diamonds. Verify supplier SADPMR registration before transacting at sadpmr.co.za.

Diamond Dealers Club member. Trade-association good-standing for SA diamond dealers. Verify at diamonds.org.za.

Jewellery Council member. Trade-association good-standing for SA retail jewellers. Verify at jewellery.org.za.

GIA Report Check. The official tool to verify a GIA diamond report number at gia.edu/report-check.

Like-for-like quote. A quote pinned to a stated carat weight, colour, clarity, cut grade and grading laboratory, with VAT inside the figure and the loose stone and the setting shown on separate lines. It is the only form in which two sellers can honestly be set against each other, because a rand number attached to a loose specification is not a price, it is an impression. Getting a quote into that shape, and knowing what else to ask while you are at it, is what the diamond buying checklist is for. Every question on it is phrased so that none of the answers depend on which shop you happen to be standing in.

FATF Recommendation 22. The international anti-money-laundering standard requiring KYC by dealers in precious metals and stones on cash transactions at or above about $15,000. Implemented in SA via FICA (Financial Intelligence Centre Act).

VAT refund. The 15 percent value-added-tax refund available to non-resident foreign buyers on purchases over R250 at OR Tambo or Cape Town airport on departure.

Sources and references

Naturaldiamond.co.za inventory study, June 2026: 230 GIA-certified natural diamonds listed by six South African sellers, each recorded with its specification and price, collected 26 June 2026.
Naturaldiamond.co.za retail price study, July 2026: 73 listings across 18 sellers, of which 17 are South African and one is an international online retailer, 71 of the rows carrying a price. Premium showrooms, mall chains and online sellers, published as bands only. See the South African diamond price index for method.
GIA grading standards and Report Check, gia.edu.
Rapaport price list, store.rapaport.com.
South African Diamonds and Precious Metals Regulator, sadpmr.co.za.

Diamond Glossary: 60+ Terms Defined for South African Buyers (2026)