What is a good diamond clarity?

For a diamond that will be worn rather than examined, VS2 is the practical target and an SI1 you have actually looked at is often just as good. GIA defines VS1 and VS2 as minor inclusions ranging from difficult to somewhat easy to see under 10x magnification, and SI1 and SI2 as noticeable inclusions that are easy or very easy to see at 10x. Note that all of those definitions describe a stone under a loupe, not a stone on a hand. Above VS2 you are buying rarity that nobody will see across a dinner table. Below SI1 you start relying on luck, so view the stone first.

What is a good diamond colour?

G or H for a white metal setting, and I or J is defensible in yellow gold. GIA groups the D to Z scale into colourless (D to F), near colourless (G to J), faint (K to M), very light (N to R) and light (S to Z), and describes the near colourless band as coloration often unseen except by trained graders. That is the whole argument for G and H. They read as white on a finger while costing meaningfully less than D, E or F, and the difference between adjacent letters is not something you can see without master stones beside the stone under controlled light.

What does eye-clean mean?

Eye-clean is the trade term for a diamond whose inclusions cannot be seen with the naked eye. GIA states plainly that this is an industry term and that GIA does not use it, which matters, because it means eye-clean appears on no grading report and is nobody's guaranteed standard. It is a judgement made by looking. Two stones both graded SI1 can differ completely on this: one has a small white crystal near the girdle and reads clean, the other has a dark crystal under the centre of the table and does not. Eye-clean is a property of the individual stone, never of the grade.

How many grades are on the GIA colour and clarity scales?

The GIA colour scale carries 23 grades from D to Z, subdivided into five groupings: colourless, near colourless, faint, very light and light. The GIA clarity scale has six categories, some of them subdivided, for a total of 11 specific grades: FL, IF, VVS1, VVS2, VS1, VS2, SI1, SI2, I1, I2 and I3. Every clarity grade is assigned under 10x magnification, and GIA's standard is that clarity, polish and symmetry grading can only be finalised using a 10x loupe. Both scales were built by GIA in the 1950s to replace trade language that meant different things to different sellers.

Is SI1 clarity good enough for an engagement ring?

Often yes, and it is where a lot of the value in the market sits, but SI1 is the first grade you must not buy blind. GIA defines SI1 inclusions as noticeable and easy to see at 10x, which says nothing about whether you can see them at arm's length. Many SI1 stones are eye-clean and cost considerably less than a VS2 that looks identical. Some are not, particularly in step cuts such as emerald and asscher, where long open facets show everything. The rule is simple: at SI1 and below, view the specific stone face-up in normal light before paying.

Why is there no SI3 grade on a GIA report?

Because GIA does not issue one. GIA states that some diamond grading laboratories issue a clarity grade of SI3, that GIA does not, and that it has studied the suggestion at various times and still sees no reason to change its system. So SI3 is not a GIA grade, it is a grade some other laboratories use, and it usually describes a stone GIA would call I1. If a South African listing shows SI3, ask which laboratory graded it and read the actual report. The grade is only as meaningful as the laboratory whose name is on it.

Does diamond colour matter more in yellow gold or white gold?

White metal exposes body colour and yellow gold masks it. A platinum or white gold setting surrounds the stone with something genuinely colourless, so any warmth in the diamond has a reference point sitting right beside it and shows more readily. Yellow gold reflects warm light into the stone and gives the eye nothing to contrast against, so a J or K that would look tinted in platinum can look perfectly white in yellow gold. This is one of the few places where the setting decision should come before the colour grade decision, because choosing yellow gold first can save you two or three colour grades at no visible cost.

Do different laboratories grade to the same standard?

They use similar terminology and they are not equally strict, and I cannot give you a number for the gap because nobody publishes a reliable one. What is documented is that the scales themselves differ: GIA declines to issue an SI3 grade that some laboratories do issue. What follows from that is a working rule rather than a measurement. A grade quoted without the name of the laboratory that issued it is not information, and comparing a stone graded by one laboratory against a stone graded by another as though the letters mean the same thing is the most common way South African buyers overpay.

Diamond Colour and Clarity Charts

Bottom line up front

Short answer: buy G to H colour with VS2 clarity, or an SI1 you have personally looked at.

It looks the same. In the great majority of stones that combination is visually identical to the grades above it and costs materially less. Everything above it is rarity nobody at a dinner table will ever see. Everything below it starts to show.
Two places to move up. Step cuts such as emerald and asscher show everything through their long open facets, so move up on both scales. Past two carats every flaw scales with the stone, so treat VS2 as a floor rather than a target and view the stone before paying.
Then buy it a step up the chain. That specification is easier to find and more plainly priced at manufacturer, cutting house or dealer level, and it is cheaper there: a counter buys at exactly that level and then roughly doubles the price, about three times at a branded showroom. Premium specification is also about five times more common up there, 52 percent of trade-access stock against 9 percent of retail-held stock.
A chart is a scale of rarity, not a scale of beauty. The two only track each other part of the way, and they separate exactly where the money starts. The question is not which grade is best, it is the lowest grade at which nobody can tell.

A counter is the better answer when the date will not move, when you would rather judge a case of finished rings on a hand than settle a grade off a chart, or when the label is part of what you want.

Both scales are printed below in full: the GIA colour chart from D to Z with its five groupings, and the GIA clarity chart with all eleven grades from Flawless to I3.

Read them with the rarity point in mind, because it decides how you use them. Every grade above the line at which nobody can tell is money spent on a certificate rather than on a diamond.

The GIA diamond colour chart, D to Z

GIA introduced the D-to-Z scale in 1953. It starts at D deliberately, so that it carried no association with the loose systems it replaced, where the same stone could be called “blue white” by one seller and “AAAA” by another. There are 23 grades, and GIA subdivides them into five groupings.

Grading is not done by holding the stone up to the light. The diamond is viewed table down, under controlled lighting, compared against a set of master stones that each correspond to a letter grade. That is why no counter can replicate a colour grade, and why you should not try.

Grade	GIA grouping	What it looks like in practice
D	Colourless	No detectable body colour. The top of the scale, priced accordingly, and indistinguishable from E or F to anyone without master stones.
E	Colourless	No body colour visible face-up. A grading distinction from D, not a visible one.
F	Colourless	Still reads fully colourless face-up. The last grade in the colourless band and usually the cheapest way into it.
G	Near colourless	Reads white in any setting. GIA describes this band as coloration often unseen except by trained graders. The value sweet spot for white metal.
H	Near colourless	Reads white face-up. Warmth is detectable only alongside a higher grade, table down, under grading light.
I	Near colourless	A faint warmth that most people never notice face-up, and that yellow gold hides completely.
J	Near colourless	Warmth becomes findable face-up in larger stones and in white metal. Excellent value in yellow gold.
K	Faint	GIA describes this band as coloration still difficult to see by the untrained eye. Visible warmth in white metal at one carat and up. Works in yellow gold.
L	Faint	Warmer again. Best suited to yellow gold, antique-style settings and smaller stones.
M	Faint	The end of the faint band. Clearly warm in white metal at any meaningful size.
N	Very light	GIA notes this band’s coloration can be seen in larger stones by the untrained eye. Tint is apparent in a one carat under white light.
O	Very light	Tint apparent face-up. Priced as a distinct commercial band rather than as a letter.
P	Very light	Tint apparent in most lighting, in most sizes above half a carat.
Q	Very light	Warm face-up. Rarely offered as a centre stone in a white metal setting.
R	Very light	The end of the very light band. Openly tinted rather than subtly warm.
S	Light	GIA describes this band as colorations that can be seen in many sized stones. Distinctly yellow or brown.
T	Light	Distinctly tinted at any size.
U	Light	Distinctly tinted. Sold on its warmth rather than in spite of it.
V	Light	Openly yellow or brown face-up.
W	Light	Openly yellow or brown face-up.
X	Light	Strong tint. Approaching the top end of the normal colour range.
Y	Light	Strong tint, still inside the normal colour range.
Z	Light	The bottom of the D-to-Z scale. Beyond a Z master stone the diamond leaves the normal range and is graded as a fancy colour instead.

GIA defines each letter as its own narrow range of colour appearance. Outside a grading environment, with master stones beside the diamond under controlled light, adjacent letters cannot be separated by eye, and from about N downwards the practical distinctions are between bands rather than between letters. Treat the third column as description, not as a grading tool.

The GIA diamond clarity chart, Flawless to I3

Clarity describes the inclusions inside a diamond and the blemishes on its surface. GIA’s scale has six categories, some subdivided, for eleven grades in total, and every one of them is defined at 10x magnification. GIA’s standard is that clarity, polish and symmetry grading can only be finalised using a 10x loupe, and a minimum of two graders record their impression of each stone.

The grade is not decided by counting inclusions. GIA weighs five factors: size, number, location, relief and nature. Hold on to “location”. It does more work on this page than any other word.

Grade	GIA category	What the grade means at 10x magnification	Visible without magnification?
FL	Flawless	No inclusions and no blemishes visible under 10x.	No. Vanishingly rare. Many jewellers never handle one.
IF	Internally Flawless	No inclusions, only insignificant blemishes, visible to a skilled grader using 10x.	No.
VVS1	Very, very slightly included	Minute inclusions, extremely difficult to see at 10x.	No.
VVS2	Very, very slightly included	Minute inclusions, very difficult to see at 10x.	No.
VS1	Very slightly included	Minor inclusions, difficult to see at 10x.	No.
VS2	Very slightly included	Minor inclusions, somewhat easy to see at 10x.	Almost never in a brilliant cut. Occasionally findable in a large step cut.
SI1	Slightly included	Noticeable inclusions, easy to see at 10x.	Usually not, but this is the grade you must view. Depends entirely on the individual stone.
SI2	Slightly included	Noticeable inclusions, very easy to see at 10x.	Sometimes yes, particularly above one carat or in a step cut. View before buying.
I1	Included	Obvious inclusions at 10x.	Commonly yes.
I2	Included	Obvious inclusions at 10x.	Yes.
I3	Included	Obvious inclusions at 10x, which may affect transparency, brilliance and durability.	Yes, and appearance is affected, not merely the grade.

A note on column three, because the attribution matters. GIA publishes its clarity definitions in grouped pairs, not per grade: “VVS1 and VVS2: inclusions so slight they are difficult for a skilled grader”, “VS1 and VS2: inclusions are observed with effort but can be characterized as minor”, “SI1 and SI2: inclusions are noticeable”. Where GIA does separate within a pair it is as a qualifier inside the shared definition, describing VVS1 as extremely difficult and VVS2 as very difficult to see at 10x. Column three splits the pairs out for readability, which is ordinary trade usage, but the split is mine and should not be read as GIA’s wording. GIA also applies the phrase about transparency, brilliance and durability to all three Included grades rather than to I3 alone. The fourth column is my practical read at normal viewing distance: it is not a GIA statement, it is on no report, and it varies stone by stone. GIA does note that most diamonds seen in jewellery stores fall between VS and SI.

The chart is not the decision

Here is where nearly every clarity chart online stops, and where the useful part starts.

Nothing in those tables describes what a diamond looks like on a hand. Every clarity definition GIA publishes is written for a trained grader looking through a 10x loupe. That is the correct way to grade a diamond and the wrong way to buy one, because you are not going to wear it under a loupe and neither is anyone who looks at it.

The trade word for the gap is eye-clean: a diamond whose inclusions cannot be seen with the naked eye. GIA is explicit that this is an industry term and that GIA does not use it. That is worth sitting with. The single most useful property a diamond can have, for the purpose of actually wearing it, appears on no grading report at all.

Which gives you the real question. Not “which grade is best”, but which is the lowest grade at which nobody can tell. In practice, for most stones:

VS2 is eye-clean. Not by rule, but close enough to it that VS2 is the sensible default when you cannot inspect the stone in person.
SI1 is frequently eye-clean too, and costs meaningfully less than VS2 at the same colour and weight. It is the best-value grade in the market and the one that requires you to look.
Above VS1 you are paying for the report. VVS and IF stones are rarer and priced for it. The rarity is real. The visible difference, on a finger, is not.

I cannot give you a percentage for how often an SI1 is eye-clean, and you should distrust anyone who does. Nobody publishes that number, it varies by shape, size and cutter, and a private buyer never sees the stones that were rejected before the tray reached them.

Five things the chart cannot tell you

1. Where the inclusion sits. This is GIA’s own location factor: the closer an inclusion is to the centre of the table, the greater its effect on the grade. The practical version matters more. A dark crystal sitting under the middle of the table is the worst possible place for it, because the table is the window you look through and the facets around it will reflect the inclusion back at you repeatedly. The same inclusion out near the girdle can disappear under the setting entirely. Two stones, same SI1 grade, completely different purchases. One caveat, and it is GIA’s: inclusions near the girdle can make a cut stone more vulnerable to damage, particularly a feather that reaches the surface, so an inclusion at the edge is a visibility win and a durability question at the same time. Ask about both.

2. What kind of inclusion it is. GIA grades relief, meaning the contrast between the inclusion and the diamond around it, and nature, the type of characteristic. A soft white cloud and a black crystal can sit at the same grade and look nothing alike. Dark, high-contrast inclusions are the ones you notice. Faint white ones frequently vanish into the sparkle.

3. The shape of the stone. Brilliant cuts hide inclusions. Their many small facets break up the light and give an inclusion nowhere obvious to sit. Step cuts do the opposite: GIA notes that clarity characteristics are typically easier to see in an emerald cut than in a round brilliant, because long rectangular facets act like open windows. Buy a step cut and move up a clarity grade. Buy a brilliant and you can usually move down one.

4. How big the stone is. Colour and clarity both become more visible as carat weight rises, because there is more diamond for the eye to look through and a larger table to look through it with. GIA’s own note on the very light band is that its coloration can be seen in larger stones by the untrained eye. The practical consequence is that a colour and clarity combination that is invisible at 0.50 ct is not automatically invisible at 2.00 ct, so grade requirements should rise with weight rather than stay fixed. The size guide sets out how much larger a stone actually gets as the weight climbs.

5. What metal it will sit in. Yellow gold masks warmth. It reflects warm light into the stone and gives the eye no colourless reference to compare against, so a J or a K can read perfectly white in it. Platinum and white gold do the opposite. They surround the diamond with something genuinely colourless and expose any warmth by direct comparison. Decide the metal before the colour grade, not after. Choosing yellow gold first can save you two or three colour grades at no visible cost, and that is real money at one carat and up.

Grading is a human judgement, and it has tolerance in it

A grading report is the best information available about a diamond, and it is still a judgement rather than a measurement. GIA’s process is built around exactly that fact: a minimum of two graders record independent colour opinions, further graders are brought in depending on agreement, weight and quality, and the grade is not determined until there is sufficient consensus. That is what a careful system for handling human judgement looks like. It is not what a machine reading looks like.

So treat a grade as a narrow band rather than a point. A stone at the bottom of G and a stone at the top of H are closer to each other than two stones sitting at opposite ends of G, and no report tells you where within the letter your stone falls.

Then there is the second problem, and it is bigger. Laboratories are not equally strict. The clearest documented instance is the scales themselves: GIA declines to issue an SI3 grade, and says so publicly, while some laboratories do issue one. When one laboratory has a grade another refuses to recognise, the letters on the two reports are not interchangeable.

I am not going to hand you a number for how far apart the laboratories run, because nobody publishes a reliable one and every figure circulating in the trade is somebody’s estimate. What follows is a working rule instead. A grade quoted without the name of the laboratory beside it is not information. Comparing a stone graded by one laboratory against a stone graded by another, as though the letters carry identical weight, is one of the most common ways a South African buyer overpays. Get the report number, verify it yourself, and read the GIA verification guide before any deposit changes hands.

What South African stock actually looks like on these scales

The charts describe a scale. They do not describe what is available to buy here, and the difference is stark.

In June 2026 I listed 230 GIA-certified natural diamonds offered by six South African sellers, each recorded with its full specification and price. Defining premium specification as D to G colour and VS2 clarity or better, which is the band this page argues is worth owning, the split was this:

Inventory type	Stones listed	Reached D to G colour and VS2 or better
Sellers working with trade access	93	52 percent
Retail-held South African stock	137	9 percent

Roughly a fivefold difference in the odds of finding the specification you came for. This is a comparison of what sits in the two kinds of inventory and nothing more. It says nothing about which is cheaper, and I am not going to use it to argue that, because per-carat figures across those two groups are not comparable.

What it does establish is why the chart above matters when you shop. If you walk into a South African retail case asking for a G VS2, roughly nine stones in a hundred on offer will meet it. The rest of the case is stocked below the line, and the cheapest ticket in it is almost always the lowest grade in it rather than the same diamond for less. Cheap per carat is not cheap per quality.

So what should you actually buy

Buying unseen, or online. G or H colour, VS2 clarity, and a cut grade of Excellent on a round. VS2 is the grade that protects you when you cannot look.
Buying in person, and willing to look. H or I colour, SI1 clarity, viewed face-up in normal light with the setting metal already chosen. This is where the value in the market lives.
Yellow gold setting. Drop two colour grades. I or J, and K is defensible. Spend what you saved on cut.
Platinum or white gold setting. Hold at G or H. The metal will expose anything warmer.
Step cut, emerald or asscher. Move up: VS1 rather than VS2, and G rather than H. Open facets show both colour and inclusions.
Two carats and above. Everything gets more visible. Treat VS2 as the floor rather than the target, and view the stone.
Never. I1 and below as a centre stone, and any grade at all from a laboratory whose report you cannot pull up yourself.

Run the rest of the pre-purchase questions from the diamond buying checklist, and if a term on a quote is unfamiliar, the glossary defines it.

The chart tells you the spec. Price tells you the seller

Once you have settled on a specification, the chart has done its job and it cannot help you further. Two sellers can quote you the same genuine one carat G VS2, on real reports, tens of thousands of rand apart. Nothing in the grading distinguishes them.

The figure that does is the per-carat price, and the useful thing about it is who will say it out loud. A seller operating at trade level will quote you a per-carat number and let you check it. A seller who will not put a number to a specification, and prefers to discuss monthly instalments or what suits your budget, has told you where the margin is. Here is a number to hold a seller to, derived from the published list so you can redo it yourself. The Rapaport round list of 20 March 2026 prices G/VS1 at 1.00 to 1.49 carats at $5,400 per carat. One carat of that, less a dealer discount off list, converted at R16.50 to the dollar and grossed up by 15 percent VAT, works out at roughly R72,000 to R92,000 for a loose stone, with about R82,000 at 20 percent off list. Set against that, my July 2026 listing work, 73 rows across 18 sellers with 71 prices among them, put a finished one carat ring at a premium South African showroom at R105,000 to R428,000, setting included, off three listings of three different specifications. Same letters on the chart. A bare stone against a finished ring, and a different question entirely.

So the search that matters is not for a shop, it is for a number. Sellers who publish what a carat costs are the ones the price question surfaces, and it is worth spending an evening on before you spend anything else. Start with what a carat actually costs in South Africa, then check any quote you receive against the South African diamond price index and the working figures on the one carat page.

Checks you run yourself

Get the report number in writing before any deposit, and verify it at gia.edu/report-check on your own device.
Read the plotting diagram, not just the grade. It maps where the inclusions sit. One drawn under the centre of the table is a different stone from one drawn at the girdle, at the same grade.
View the stone face-up at arm’s length before anyone hands you a loupe, then loupe it. That order tells you whether it is eye-clean, the only clarity question that changes how it looks.
Choose the metal first, then set the colour grade against it.
Compare two stones one grade apart, unlabelled, at the same weight. Most people cannot pick the higher one, and the ones who cannot have just saved themselves real money.
Ask which laboratory graded it, every time, and treat an unfamiliar laboratory’s letters as a different currency.
Ask for the per-carat price on the loose stone, separated from the setting, before anything else.

Sources and references

Clarity scale, definitions and the five grading factors: GIA on diamond clarity and Seven Things You Need to Know About Diamond Clarity, which is also where GIA’s eye-clean and SI3 statements come from.
D-to-Z colour scale, groupings and grading method: GIA on diamond colour, Diamond Color Chart: The Official GIA Color Scale and The GIA Guide to Diamond Color.
Grading procedure and the two-grader consensus: GIA colour grading Q&A and GIA clarity grading Q&A.
Report verification: GIA Report Check.
My June 2026 inventory study: 230 GIA-certified natural diamonds listed by six South African sellers, each recorded with specification and price, collected 26 June 2026.
My July 2026 price study: 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. Published as bands only. Method in the price index.
Rapaport round brilliant price list, 20 March 2026: the published asking-price benchmark the loose-stone figures above are derived from, at $5,400 per carat for G/VS1 in the 1.00 to 1.49 carat bracket.

What I do not know, and will not guess at: how often a given SI1 turns out to be eye-clean, and how far apart the grading laboratories actually run. Both would need a controlled sample nobody has published. For how I research and correct these pages, see the editorial policy.

Diamond Colour and Clarity Charts (2026): The Full GIA Scales, and the Grade Worth Paying For