The top lot at the 2025 Arqana Deauville August Yearling Sale was a blueblood St Mark’s Basilica filly from blue hen Prudenzia that sold for €1.7million to MV Magnier and she became the first Group I winner for her sire when charging home to win the Group I Prix Marcel Boussac (1600m) at Longchamp.
Trained by Aidan O’Brien and ridden by Christophe Soumillon, Diamond Necklace won a maiden in August, a Listed race in September and continued her swift ascension with a stylish length victory as favourite to keep her record at a perfect three for three.
“We thought Diamond Necklace was a bit babyish to come here but Christophe [Soumillon] rode her at Leopardstown and he said to let her come and we'd leave her alone after that for the year,” said Aidan O’Brien.
“We've only really seen the St Mark's Basilicas coming to hand in the last month or six weeks. St Mark's didn't win his first G1 race until the Dewhurst, and we all know what he did at three, so they are obviously very like him.
“She is up there, and Precise is very good as well. We try to give them all their chance of winning a Group 1 before coming back for a second one, so this was her chance. I'd imagine she's finished for the year now. I'd say she will probably start with a Guineas prep like we do with them all and we'll take it from there. She's not short of speed and is going to be a lovely Classic filly.”
Diamond Necklace runs for the Coolmore partners and was bred by Ecurie des Monceaux and Skymarc Farm. She is the half-sister to Group I winners Magic Wand and Chiquita (dam of Group II winner Emily Dickinson), as well as Group III winner Philomene.
She is the ninth winner and third G1 winner from 10 foals to race from stakes-winning Dansili mare Prudenzia.
Diamond Necklace is the first G1 winner among three stakes-winner for St Mark’s Basilica, who has sired 17 winners.
The 2021 European Horse of the Year is back at Coolmore Australia at a fee of $38,500 and will have his first Australian 2YOs racing this season.
