A Siyouni half-brother to €1.7-million Arqana August graduate and dual French Classic winner Diamond Necklace (St Mark's Basilica) leads the 325-strong catalogue for the 2026 edition of the sale in Deauville. The sale will take place from Saturday, August 15 through Monday, August 17. Sessions for the first two days will begin at 5:30 p.m. local time, while Monday's session will start at 11 a.m.Set to sell as lot 128, the colt is out of stakes winner Prudenzia (Dansili) and is a half-brother to four stakes winners, with Irish Oaks heroine Chicquita (Montjeu) and Mackinnon Stakes victress Magic Wand (Galileo) joining Diamond Necklace as Group 1 scorers.GI Breeders' Cup Juvenile Fillies Turf heroine Balantina (Ten Sovereigns) and G1 Jebel Hatta victor Opera Ballo (Ghaiyyath) have also flown the flag for Arqana in the past year, as has Constitution River (Wootton Bassett). The winner of the 2026 G1 Prix du Jockey Club, he is represented by a half-sibling, with lot 287, a Kodiac filly, lining up on day three.There are no fewer than 18 siblings to Group 1 winners catalogued, including lot 8, a full-sister to Fantastic Moon (Sea The Moon); a Siyouni half-brother to Feed The Flame (lot 52); an Erevann half-sister to Metropolitan (lot 237); a full-brother to Native Trail (lot 94); a Justify colt who is a half-brother to Sioux Nation (lot 314); G1 Prix de Diane heroine Sparkling Plenty (Kingman)'s full-brother is lot 187; a full-brother to Tamfana (Soldier Hollow) (lot 207); and a Wootton Bassett full-brother to GI Breeders' Cup Juvenile Turf scorer Unquestionable is lot 189.Other pedigrees of note include: a Sea The Stars filly (lot 73) who is a half-sister to group winner and German Derby-placed Mr Hollywood (Iquitos); lot 115, a Chaldean half-sister to multiple group winner Eternal Pearl (Frankel), herself a half-sister to G1 Matron Stakes winner Pearls Galore (Invincible Spirit); lot 120, a Frankel filly out of group winner and G1 Prix de Diane second Philomene (Dubawi) from the same family as Diamond Necklace; a Dark Angel colt (lot 130) out of G1 Oaks heroine Qualify (Fastnet Rock); lot 260 is a half-brother to group winners Map Of Stars (Sea The Stars) and Tajlina (Kingman) with the trio out of G1 Prix Jean-Luc Lagardere heroine Bateel (Dubawi); and a Wootton Bassett colt out of a full-sister to multiple Group 1 winner Scandinavia (Justify) is lot 306.Some of the world's best stallions are represented at Arqana, including: Blue Point, Camelot, Frankel, Justify, Kingman, Lope de Vega, Mehmas, New Bay, Night Of Thunder, No Nay Never, Not This Time, Sea The Stars, Siyouni, Starspangledbanner, Too Darn Hot, Wootton Bassett and Zarak. First-season sires are well represented, among them Ace Impact, Chaldean, Erevann, Good Guess, Little Big Bear, Mishriff, Modern Games, Mostahdaf, Onesto, Paddington, and Vadeni.In 2025, the sale grossed €57,647,000 for 216 sold from 272 offered (79.4%). The average was €266,884 and the median was €165,000. Topper honours went to a Night Of Thunder half-sister to Diamond Necklace, et al, when purchased by Amo Racing for €3 million. She has since been named Marylebone.The post Diamond Necklace Half-Brother Leads Star-Studded Arqana August Catalogue appeared first on TDN | Thoroughbred Daily News | Horse Racing News, Results and Video | Thoroughbred Breeding and Auctions.