Grey and Salt and Pepper Diamond Guide: Colour, Grades and Settings

What is a grey diamond, and how is a salt and pepper diamond different?

In the diamond trade, grey diamonds and salt and pepper diamonds are often shown side by side, but they are not the same thing. A grey diamond is a fancy colour diamond: its body colour (the overall colour of the stone itself) is a cool, steely grey, and a lab grades it on the same system used for pinks, blues and yellows, which is explained in our guide to fancy colour diamonds. Many grey diamonds are reasonably clean inside and can be transparent and bright.

A salt and pepper diamond gets its look from inclusions rather than body colour. Inclusions are the internal features a natural diamond grows with. Here they are plentiful: black specks (the pepper) and white clouds, pinpoints and feathers (the salt) scattered through the stone. The result looks a little like granite or a night sky, and no two stones are alike. Most are graded I1 to I3 for clarity, the lowest end of the scale, which is why they cost much less than a clean diamond of the same size.

Grey also turns up as a faint nuance, a slight greyish cast, in diamonds sold as near-colourless. That is a separate question, covered in grey nuance in diamonds that look colourless. If any term on this page is new to you, our jewellery glossary explains it in plain words.

What causes grey diamonds?

Diamond is carbon arranged in a tight crystal, 10 on the Mohs hardness scale, with a refractive index of about 2.42. Perfectly pure diamond is colourless. Grey appears when something in the crystal absorbs light evenly across the spectrum, or when tiny particles block and scatter it. There are four main causes:

Boron is the same element that colours boron-coloured blue diamonds, which is why a grey diamond can carry a bluish modifier, and why Type IIb diamonds conduct electricity, something a gemmologist can test. Hydrogen is linked to the grey-violet stones that sit on the border with violet and purple diamonds. When dark inclusions become so dense that light cannot pass through at all, you have moved into opaque black diamonds, most of which are treated.

How are fancy grey diamonds graded for intensity?

GIA and other labs grade fancy colour by hue (the colour itself, here grey), tone (how light or dark it is) and saturation (how strong it is). Grey is by nature a low-saturation colour, so its scale is shorter than for pink or yellow: there is no Fancy Intense or Fancy Vivid Grey. For grey, the grade words mostly describe how light or dark the stone is.

Many greys also carry a modifier, a secondary colour named before the main one: Fancy Bluish Grey, Fancy Greenish Grey, Fancy Violetish Grey or Fancy Yellowish Grey. The last word is always the dominant colour. A bluish or violetish modifier usually adds value; a yellowish or brownish one usually does not. Our pages on how modifiers and overtones are written on reports and the full intensity scale from Faint to Vivid show how grey fits in with every other fancy colour.

How do you judge a salt and pepper diamond?

Because the inclusions are the whole point, a salt and pepper diamond is judged differently from a white diamond. The clarity grade tells you very little on its own. What matters is how the pattern looks to your eye and whether the stone is structurally sound. Check these five things:

• Pattern balance: evenly spread speckling, or a deliberate feature such as a cluster to one side. A heavy dark mass right in the centre can read as a hole from a metre away.
• Overall tone: stones with mostly white 'salt' look light and silvery; mostly black 'pepper' looks charcoal. Decide which you prefer before comparing.
• Transparency: some are translucent with movement inside; others are close to opaque. A little light passing through usually looks livelier.
• Feathers: feathers are small internal cracks. Those that reach the surface, especially near the girdle (the outer edge) or a point, reduce toughness.
• Cut: rose cuts, hexagons, kites, shields and elongated shapes are common. A rose cut has a flat base and a domed top with a few large facets, so it shows the inclusions like a window. A brilliant cut breaks the pattern up into more sparkle.

Diamond's hardness means the surface will not scratch from everyday wear, but toughness, resistance to chipping and breaking, is lower in a heavily included stone. Many salt and pepper diamonds are also cut shallow to show off the pattern. A bezel or a setting with claws over any points makes a salt and pepper diamond engagement ring practical for daily wear. If a stone has surface-reaching feathers, ask your jeweller before using an ultrasonic cleaner, as the vibration can stress existing cracks.

Did the Argyle mine produce grey diamonds?

The Argyle mine, in the east Kimberley of Western Australia, operated from the mid-1980s until it closed in November 2020. It is famous for Argyle pink diamonds and for a handful of the rarest red diamonds ever found. By volume, though, most of its output was brown, which Argyle marketed on its own scale; see champagne and cognac browns from Argyle.

Argyle also produced a small number of grey, grey-blue and violet-grey diamonds, coloured by hydrogen rather than boron. Argyle grey-violets and blues were offered in the mine's annual tender alongside the top pinks, and they are now very hard to find. An Argyle violet-grey with original documentation is priced stone by stone and sits far above an ordinary grey diamond. If a stone is sold as Argyle, ask for the Argyle certificate or a laser inscription that matches it.

For ordinary greys and salt and pepper diamonds, the mine of origin is rarely recorded. Treat any origin claim with care unless it comes with documentation you can verify.

Is a grey diamond natural, lab-grown or treated?

Grey colour can be natural, grown in a laboratory or produced by treatment, and you cannot tell which by eye. The grading report is the only reliable answer. GIA's coloured diamond reports include a colour origin line (printed in US spelling on the report itself). Here is how to read it, with examples of what you might see:

Lab-grown grey diamonds are real diamond with the same hardness and refractive index as natural, grown either by CVD (chemical vapour deposition, built up layer by layer from a carbon-rich gas) or HPHT (high pressure, high temperature). CVD crystals can grow with a grey or brown tint; see why some CVD lab-grown diamonds show a grey tint. HPHT growth with a little boron gives grey to grey-blue. A lab-grown stone should always be sold as lab-grown, and most are laser-inscribed on the girdle to say so. Lab-grown salt and pepper stones are uncommon, because the look depends on natural inclusions.

Treatment is less common in grey and salt and pepper diamonds than in black ones, but it exists. Heavily included stones can also be fracture-filled (cracks filled with a glass-like material) or coated; GIA does not issue a full grading report for a fracture-filled diamond. Any treatment must be disclosed, so ask directly and check the report.

How does a salt and pepper diamond compare with grey, black and champagne diamonds?

The choice usually comes down to transparency and pattern. A fancy grey looks like a cool, clean diamond; a salt and pepper looks like a natural material with a story in it; a black diamond gives a solid, polished surface with no sparkle at all. If you want stronger colour instead, compare yellow and canary diamonds, green diamonds coloured by natural radiation or warm orange diamonds.

Outside diamond, natural grey spinel (about 8 on the Mohs scale) gives a similar steely colour, though it is softer than diamond and scratches more easily in an everyday ring.

How much does a salt and pepper diamond cost in Australia?

Prices vary widely because these stones are valued on looks rather than strict grades. The ranges below are broad guides for about 1 carat only; the market moves and individual stones can fall well outside them.

For salt and pepper stones, what moves the price most is the look of the pattern, the cut quality and how much light passes through; a balanced, translucent stone costs more than a muddy one of the same weight. For fancy greys, the intensity grade, any modifier (bluish and violetish add value), clarity and colour origin matter most. Lab-grown greys cost much less than natural greys of similar appearance.

What are the best settings and metals for grey and salt and pepper diamonds?

Metal changes how grey reads more than almost any other fancy colour, because grey has little colour of its own to push back.

• White gold or platinum: keeps the grey cool and steely. The most neutral choice for a fancy grey.
• Rose gold: warm metal against cool grey gives clear contrast and softens a dark stone.
• Yellow gold: a stronger, vintage-feeling contrast; it can warm the white 'salt' slightly.
• Black rhodium: a dark plating on white gold for a moody, monochrome look. It wears with time and needs replating.

• Bezel: a rim of metal around the edge. Very protective, ideal for shallow rose cuts and stones with feathers.
• Claws with V-claws on points: show more of the stone; good for hexagons and kites if every point is covered.
• Halo of white diamonds: frames a dark or speckled stone and makes it look larger.
• Salt and pepper or grey side stones: for a tonal, matched design.

Our guide to settings and metals for coloured diamonds has side-by-side examples across every colour, including how a matching wedding band sits beside an irregular shape.

How do you choose a grey or salt and pepper diamond? Step by step

1. Decide on the look. Even grey colour (fancy grey) or a patterned stone (salt and pepper).
2. Read the report. Check the colour grade and modifier, clarity, measurements and the colour origin line, and confirm natural or lab-grown.
3. Look at arm's length. Judge pattern balance and transparency in daylight and under shop lighting.
4. Check soundness. Under a loupe, look for feathers reaching the surface, especially at the girdle and any points.
5. Ask about treatment. Confirm whether the stone is untreated, treated, filled or coated.
6. Match the metal. Hold the stone against white, rose and yellow metal before deciding.
7. Plan a protective setting. A bezel or covered points, especially for shallow or heavily included stones.