The signet, in onyx and diamond.A ten-by-fourteen-millimetre polished black onyx at the face, hand-selected for an even matte field with no banding. Point-zero-seven carats of round-brilliant diamond accent the shoulder in fourteen-karat white or yellow gold.Unmistakably Isaac Westman.

The solitaire, in garnet.A six-by-eight-millimetre oval garnet at the centre, hand-selected at the source for the deep red saturation. Bezel-set in fourteen-karat white gold, the metal running continuously around the stone. The band is finished to a single polished line beneath.The best jewels make...

Smoky quartz, set in yellow gold.A ten-by-twelve-millimetre oval smoky quartz at the centre, hand-selected at the source for the warm topaz-brown depth that runs through the cut. Set in fourteen-karat yellow gold, finished to a single polished surface around the stone with the band...

A fifteen-millimetre smoky quartz, in yellow gold.A fancy-cut smoky quartz roughly fifteen-by-fifteen millimetres at the face, hand-selected at the source for the warm topaz-brown depth. Set in fourteen-karat yellow gold with a rope-twist bezel and an open gallery beneath the stone, so light passes...

Four rubies, set with three diamonds.Four round rubies and three round-brilliant diamonds — point-two-six carats in total — set along the face of a fourteen-karat white gold band. The rubies are hand-selected at the source for the deep red saturation; the diamonds carry the...

Emerald, set with round-brilliant diamond.A created emerald at the centre, chosen for the deep green saturation that defines the cut, paired with round-brilliant diamond accents in fourteen-karat gold. The metal is shaped and finished in the New York atelier, the band closing flush around...

A heart of pink sapphire, set with diamond.A five-millimetre heart-shaped pink sapphire at the centre, with point-one-seven carats of diamond running along the shoulders in fourteen-karat white gold. The stone carries the colour, the diamonds frame it.The best jewels make the best gifts.

A heart of pink sapphire, ringed in diamond.A five-millimetre heart-shaped pink sapphire at the centre, hand-selected for the rose saturation, framed by point-two carats of round-brilliant diamond in fourteen-karat white gold. The halo holds the stone forward; the band is finished to a single...

Pink sapphire, held in a split band.An oval pink sapphire at the centre, hand-selected at the source, with point-three carats of round-brilliant diamond along a split fourteen-karat white gold band. The sapphire carries the colour; the diamonds carry the geometry.Heirlooms in the making.

Peridot, set with round-brilliant diamond.An eight-by-eight-millimetre peridot at the centre, hand-selected at the source for the olive-green saturation that defines the August birthstone. Point-one carats of round-brilliant diamond accent the shoulders in fourteen-karat white gold; the band closes flush around the stone.The best jewels...