Gemstone Jewelry

Where a listing names a gemstone, that is real gemstone material - either mined or grown in a laboratory. Laboratory-grown material is the same mineral as its mined counterpart, with the same chemistry, hardness and optical behaviour; the difference is where the crystal formed, not what it is.

This page also includes designs that use cubic zirconia, sometimes as the only stone and sometimes as accents set around a coloured centre. Cubic zirconia is a man-made material, not a gemstone, and it is named as such wherever it is used.

So the answer is on the individual listing rather than the collection: each one states the stone or stones, whether they are mined, laboratory-grown or cubic zirconia, along with the metal and the dimensions.

Start with colour, because in coloured stones it carries more weight than anything else. Look at hue - how pure the colour is and whether it leans toward a neighbour - then saturation, then tone. Strong saturation at a medium tone is what the trade prizes.

Then read clarity against the species rather than against a diamond. Some minerals are expected to show internal features and some are expected to be clean, so the same appearance can be excellent in one stone and poor in another.

Cut matters last but is not nothing: a well-cut stone returns light evenly across the face rather than showing a dull centre. Judge from the photographs and the stated millimetre dimensions on the listing.

Hardness is measured on the Mohs scale, and it is a property of the mineral rather than of any individual piece. Sapphire and ruby are both corundum at 9 and are among the most practical coloured stones for a ring worn daily. Spinel and topaz sit at 8. Aquamarine and morganite are around 7.5 to 8.

Amethyst, citrine and most garnet sit near 7, which is workable in a ring but benefits from a setting that protects the stone's edges.

Tanzanite, opal, moonstone and turquoise are the ones to think twice about in an everyday ring - not because they are poor stones, but because a hand takes more knocks than an ear or a neckline does. In earrings or a pendant they are entirely practical.

A gemstone is the mineral itself, whether it grew in the ground or in a laboratory. A simulant is a different material chosen because it resembles that mineral - cubic zirconia standing in for diamond, or glass and synthetic spinel standing in for coloured stones.

The distinction is not about appearance but about identity. A simulant has different hardness, different optical properties and a different value basis, even when a photograph makes the two look alike.

Both are represented on this page and both are named plainly. A listing that says lab-grown sapphire means the mineral grown under controlled conditions; a listing that says cubic zirconia means the man-made simulant. Read the stone description on the piece itself before deciding.

Most coloured stones sold anywhere have been treated, and the common treatments are long-established rather than something to be wary of in principle. Heating is routine in sapphire, ruby and aquamarine and is considered stable. Emerald is commonly oiled or resin-filled. Some blue topaz is irradiated and then heated.

It matters for two reasons. Value: an untreated stone of good colour generally sits above a treated one. And care: filled or fracture-treated stones must be kept away from heat, solvents and ultrasonic cleaning, which can disturb the filler.

Treatment belongs to the individual stone rather than to a category, so check the specific piece if it will affect your decision.

Both 14K gold and platinum are used across this collection, and in the gold pieces the colour - yellow, white or rose - is generally chosen at the point of order rather than being a separate product.

As a rule of thumb, a cool metal lets a stone's own colour dominate, and a warm metal adds warmth to it. Yellow gold flatters warm stones such as citrine, garnet and yellow sapphire and reads traditional with green and blue. White metals give blue, violet and green stones a cleaner background. Rose gold is a deliberate contrast against green and blue and sits very naturally with morganite and pink stones.

The practical tie-breakers are usually what the wearer already owns and how heavy they like a piece to feel, since platinum is denser than gold.

Carat is a unit of weight, not of size. Two stones of the same carat weight can look noticeably different in a setting because gem species differ in density - a one-carat stone in a dense species is physically smaller than a one-carat stone in a light one.

That is why most listings here give the stone's dimensions in millimetres. Millimetres describe what you will actually see once the piece is on.

Where a total carat weight is quoted for a design, it covers every stone in the piece including any accents, so on a halo or a cluster it is not the weight of the centre stone alone.

Many of these pieces are made for exactly that, and the question is which stone in which form. A sapphire or ruby in a bezel or a low setting is about as practical as a coloured stone gets on a hand.

Softer and more fragile stones are better placed where they take less impact. The same opal that would worry you in a daily ring is an easy choice as a pendant, because a neckline simply does not meet door frames and worktops the way a hand does.

Whatever the stone, taking a ring off for manual work, sport and cleaning removes most of the real risk, and having the setting checked by a jeweller from time to time is sensible on any piece worn constantly.

Warm water with a little mild soap, a soft brush around the setting, a thorough rinse and a soft cloth suits the great majority of stones here.

Avoid ultrasonic and steam cleaners. They are a genuine risk to stones that have been filled, to any stone with a fracture reaching the surface, and to porous material such as opal and turquoise. Keep all coloured stones away from solvents and household cleaning products.

Store pieces so that nothing harder rests against them. Hardness differences do their damage in a jewellery box as easily as in wear - a sapphire will scratch an amethyst sitting next to it.

The stones represented here are sapphire, ruby, emerald, amethyst, garnet, peridot, aquamarine, citrine, topaz, tourmaline, zircon, tanzanite, turquoise, opal, moonstone, alexandrite, onyx, morganite, spinel and moissanite.

Between them they account for every modern birthstone month except April, whose stone is diamond and which lives with the diamond collections instead, and they include several stones outside the birthstone lists entirely.

If you are shopping for a particular month rather than a particular mineral, the birthstone pages group the same material by month instead, which is usually the faster route when the occasion is a birthday.