Sapphire Jewelry

No. Corundum occurs in pink, violet, yellow, orange, green, grey, black and colourless as well as blue, and all of those are sapphire. Only the red variety is given a different name.

The trade calls the non-blue stones fancy sapphires. Yellow and pink are the most commonly seen, and colourless material is sold under the name white sapphire.

Blue is what most people picture because blue built the stone's reputation over centuries. The other colours are the same mineral with a different trace element sitting in the lattice.

Colour, and nothing else. Both are corundum. Chromium in the crystal produces red, and where that red is saturated enough the stone is called ruby.

Everything short of that threshold, pink included, is sold as sapphire. The line has never been drawn identically in every market, so a stone described as pink sapphire in one country may be called a light ruby in another.

Because the material is identical, hardness, care and setting requirements are the same for both, and a jeweller works them in the same way.

It means the stone resists scratching from almost everything it will meet. Airborne dust contains quartz at 7, which is what gradually dulls softer stones; corundum is untouched by it.

Facet edges therefore stay crisp and the polish holds, which is why sapphire is one of the few coloured stones that suits a ring worn constantly.

Hardness says nothing about impact. A sharp knock on an exposed corner can still chip a sapphire, so a setting that keeps the girdle protected remains worthwhile.

Most blue sapphire on the market has been heated, and the practice is long established and openly declared rather than concealed. It is the normal condition of the material rather than an exception to it.

Heating dissolves fine internal needles and improves colour and transparency. The change is permanent, and it makes no difference to how a piece should be cleaned or worn.

It matters commercially rather than practically. Unheated stones of good colour are scarce, so the distinction is recorded, and a laboratory report on a larger stone will note whether heat was detected.

Yes, in the sense that matters. It is corundum, with the same composition, the same hardness of 9 and the same optical properties as mined material. It is not a simulant such as cubic zirconia, which imitates the look using a different substance.

The difference is origin. One crystallised in the earth across a geological span; the other grew in weeks under controlled conditions.

Grown stones tend to be cleaner and more even in colour, because the conditions were held steady throughout growth. That evenness is useful wherever two closely matching stones are needed.

By looking inside it. Flame-fusion material shows curved growth striae and small spherical gas bubbles, and neither of those forms in nature.

Mined corundum carries straight, angular colour banding and inclusions of other minerals that grew alongside it. Flux-grown stones are harder work, since flux residue trapped during growth can resemble a natural inclusion.

Modern growth methods narrow the visual gap, which is why a report from a recognised gemmological laboratory is the dependable answer rather than an opinion formed across a counter.

A sapphire of a particular pink-orange colour, named from the Sinhalese word for lotus blossom. It is the only fancy colour to have acquired a name of its own.

The definition is narrow and much argued over. Stones leaning too far toward pink or too far toward orange are usually described simply as pink sapphire or orange sapphire.

Material that genuinely answers the description is scarce, and it is judged against that scarcity rather than against blue sapphire of similar size.

Fine needle-like inclusions of rutile, aligned along three directions within the crystal. Light striking each set of needles is reflected back as a band running perpendicular to them.

Three intersecting bands produce a six-rayed star. The effect is called asterism, and it appears only when the stone is cut as a domed cabochon with the dome correctly oriented.

Because those needles are the same inclusions that heating dissolves, star material is not treated in the usual way. The thing to judge is whether the star is sharp and whether it travels cleanly as the stone is tilted.

It matters as far as it is visible. Zoning is banded or patchy colour within the crystal, and sapphire almost always has some. The question is whether it reads through the face of the finished stone.

A well-oriented cut spreads the colour so the stone appears even from the front. Zoning visible only through the pavilion, from the side, is of little consequence once the stone is set.

Look at the stone face-up in more than one light. If a pale band crosses the table, or the centre looks washed out while the edges hold colour, that is the cut speaking.

Not closely, once the two are seen together. White sapphire is colourless corundum, and it returns light in a softer, greyer way because it bends light less strongly and disperses it far less.

A diamond splits white light into spectral colours to a degree sapphire cannot, which is the flash people recognise. Sapphire reads quieter and slightly milky beside it.

What the two share is hardness. As a colourless stone for constant wear, white sapphire keeps its polish where softer alternatives go cloudy.