agate /ˈægət/ ágata: A long necklace of gold beads and polished agate fell across her breasts.

amethyst /ˈæməθɪst/ amatista: A favourite of kings and queens, amethyst can be found in the British Crown Jewels and the jewellery of Egyptian royalty.

aquamarine /ˌækwəməˈriːn/ aguamarina: Her only jewelry is a pair of sparkly aquamarine earrings.

diamond /ˈdaɪəmənd, ˈdaɪ-/ diamante: a diamond ring ^ diamond earrings ^ During the Black Death, English aristocrats wore diamonds believing they could keep the disease at bay.

emerald /ˈemərəld/ esmeralda: The emerald formed the unmistakeable shape of an eye.

garnet /ˈgɑːnɪt/ granate: a garnet brooch

jade /ʤeɪd/ jade: A chunky choker of garnet and jade circled her neck.

jasper /ˈʤæspə/ jaspe: The stones used included red jasper.

jet /ʤet/ azabache jet-black negro azabache: jet-black hair

lapis lazuli /ˌlæpɪsˈlæzjʊli/ (also lapis) lapislázuli: Around the skeleton's neck were beads and amulets of lapis lazuli, the much-prized blue stone from eastern Afghanistan.

moonstone /ˈmuːnstəʊn/ piedra lunar: A moonstone glowed in its silver setting as it rested on her forehead. ^ He noticed that she wore a moonstone ring.

onyx /ˈɒnɪks/ ónice: Centuries ago, cameos were carved on onyx or other precious stones.

opal /ˈəʊpəl/ ópalo: He was cracking open rocks looking for opal. ^ opal mining

ruby /ˈruːbi/ rubí: Around her long and delicate throat was an exquisite pendant with a large central ruby from which dangled three tear-shaped pearls.

sapphire /ˈsæfaɪə/ zafiro: a sapphire ring

topaz /ˈtəʊpæz/ topacio: He bought her a topaz pendant.

tourmaline /ˈtʊəməliːn, ˈtɜː-, ˈtɔː-/ turmalina: I drove to this little enclave yesterday in search of a grotto that is supposed to be full of tourmaline.

turquoise /ˈtɜːkwɔɪz, -kwɑːz/ turquesa: He always wore a turquoise ring that belonged to his sister, who got cancer or something horrible like that.

IDIOMS

the Emerald Isle (la verde) Irlanda: “I'm the most wanted man on the Emerald Isle. Except I'm not on the Emerald Isle, of course, more's the pity.” [Braveheart (1995)]

be a rough diamond (British English) / (American English be a diamond in the rough) ser un diamante en bruto: He's rather a rough diamond, but terribly clever.