Gemstones

Diamond

"The diamond does not ask to be noticed. It simply is."

Clarity, restraint, permanence. We use diamonds sparingly, as an accent rather than the headline of a piece, in keeping with how we see luxury overall.

A diamond is carbon, and nothing else, formed under heat past a thousand degrees and pressure found only some hundred and fifty kilometres beneath the earth's surface, held there for a billion years or more before a volcanic pipe carries it, by chance, back to where a hand can find it. It is the hardest natural material known, a ten on the Mohs scale, which is why it can be cut with such exactness and worn for a lifetime.

Value is read through the four Cs: cut, colour, clarity and carat. We also look for stones with a traceable, responsible origin. For a full guide, see our Diamond Education.

Sapphire

"Blue is only the beginning of what a sapphire can be."

Sapphire, like ruby, is corundum, and the name covers every colour the mineral comes in except red. Blue, caused by traces of iron and titanium, remains the colour most associate with it, but sapphire also occurs in pink, yellow, violet and a rare pinkish orange called padparadscha, named for the lotus blossom. At nine on the Mohs scale, just below diamond, it is one of the most practical gemstones for a piece worn often.

Kashmir produced the most storied blue, velvety and slightly milky, though its mines have been largely exhausted for over a century. Sri Lanka, Myanmar and Madagascar continue to produce fine material, and heat treatment to improve colour is standard and accepted practice.

Ruby

"Where other stones catch the light, the ruby holds it."

Ruby is corundum coloured red by traces of chromium. It is the second hardest natural mineral after diamond, a nine on the Mohs scale, and one of the few coloured stones suited to daily wear. The finest rubies have historically come from Myanmar, where the most prized hue has a name of its own, pigeon's blood: a saturated red with a faint undertone of blue. Fine material is also found in Mozambique and Thailand.

Fine silk-like inclusions can soften a ruby's glow and are often a mark of natural origin. Heat treatment is accepted when disclosed, while invasive treatments such as glass filling are not something we work with.

Emerald

"An emerald keeps its own history, visible if you look closely enough."

Emerald is a variety of beryl, coloured by chromium and vanadium, two elements that rarely meet beryllium in the same rock. That scarcity has always placed fine emerald among the most valuable coloured stones. At seven and a half to eight on the Mohs scale, and typically included, it asks for a gentler hand, and shows at its best in pendants and earrings, or rings worn with care.

Its inclusions are so characteristic that the trade calls them jardin, French for garden. Colombia remains the benchmark for a vivid, slightly bluish green, with Zambia and Brazil producing fine stones of their own.

Pink Sapphire

Pink sapphire belongs to the same corundum family as ruby and blue sapphire, and the line between ruby and pink sapphire is drawn by colour alone: when the red is strong enough, the stone is a ruby; when it softens to pink, it remains a sapphire. With the same hardness as its relatives, it is a durable and joyful choice, usually more accessible than a ruby of similar size.

Tanzanite

Found in only one place on earth, the Merelani Hills at the foot of Mount Kilimanjaro, tanzanite was discovered in 1967. Its colour moves between violet and deep blue depending on the angle and the light. At around six and a half on the Mohs scale it is softer than the four precious stones and asks for a little care, yet it is as rare as many of them. Discover it in our Zanite rings.

Opal

Opal is known for its play of colour, flashes of every hue that move across the stone as it turns, created as light diffracts through tiny spheres of silica inside it. Solid opals are cut from a single stone, while doublets and triplets layer a thin slice of opal over a darker base. Opal is soft and holds a little water, so it asks for gentle wear. Learn more in our Opal Education.

Amethyst

"Some colours are inherited, not chosen."

Amethyst is a variety of quartz, coloured purple by iron and natural irradiation within the earth. Once ranked among the cardinal gemstones alongside diamond, ruby, sapphire and emerald, it became more widely available after large deposits were found in Brazil in the nineteenth century. The most prized colour is a deep, saturated purple with flashes of red.

For us, amethyst carries a meaning beyond the stone. Its deep, regal purple became the signature colour of this Maison, a quiet thread running through our collections.

Topaz

One of the most loved coloured stones, topaz is hard, clear and remarkably good value. Blue topaz is recognised in three tones: Sky Blue, the palest; Swiss Blue, a bright, clear mid blue; and London Blue, the deepest and most inky. You will find blue and London blue topaz side by side in our Kyanos pieces, part of the Spectrum collection.

Peridot

Peridot is one of the few gemstones that comes in a single colour: green. That colour comes from iron within the stone itself rather than from trace impurities, which is why it never strays far from its fresh, almost lime green. It glows especially well against yellow gold, as in our Spectrum pieces.

Garnet

Garnet takes its name from the Latin granatum, pomegranate, for the likeness of its deep red crystals to the fruit's seeds. Garnet is in fact a family of stones, found in many colours beyond red.

Rhodolite

One of the most beautiful members of the garnet family, rhodolite is lighter and brighter than classic garnet, a rosy pink red with more sparkle.

Moonstone

Moonstone owes its name to the soft, floating glow that seems to move beneath its surface, an effect called adularescence, created as light scatters between fine layers within the stone. Associated with the moon since antiquity, it is one of the gentlest stones to wear. Discover it in our Kyanos Moon Earrings.

Hematite

Hematite is a form of iron oxide, and its name comes from the Greek for blood, because the stone turns red when cut or ground to powder. Polished, it shows an almost metallic, silver grey shine. Unlike most gemstones it is opaque, so its beauty lies in its surface and lustre.

Onyx

Onyx is a banded form of chalcedony, a variety of quartz. Most often seen in deep black, it also occurs in white and in red brown, when it is known as sardonyx. Its smooth, even surface makes it a classic choice for cabochons, signet rings and inlaid designs.