Christie’s New York, June 16 – 30

For this season’s online jewelry auctions, Christie’s has a summer cooler of epic proportions: a 28.86-carat diamond ring. Its bona fides are everything a truly distinguished diamond should have and every diamond connoisseur would want. The elegant emerald cut is a magnificent platform for showing off this D color, VVS1 clarity, Type IIA diamond. It is also the highest valued lot ever to be offered online by the house, with an estimate of $1,000,000–2,000,000. This is a diamond of rare quality.

For those who garden, there’s an enchanting Van Cleef & Arpels Rose de Noel floral brooch, the heart-shaped leaves in green chrysoprase and trimmed in gold, as well as a Graff “Classic Butterfly” ladies watch—pink sapphire butterflies airborne on diamond clouds.

Bonhams Knightsbridge, June 10 – 23

In the 1960s, British jeweler Roy King was among those who changed the look of watches and jewelry, with clients such as the Beatles knocking at his door. At Bonhams Knightsbridge you have a chance to snag one of his watch-bracelets from the period. It’s fancier than usual for King, having a hidden face cased in diamond-set gold. The fashion appeal of Chanel shows in a sweet little violet ring, in amethyst with a pavé-set garnet leaf. And what’s gentler than pink tourmaline, especially when made into a ring by the Roman house of Bvlgari, who know a thing or two about hot weather.