Leighton and Olivia at the Swarovski Book Launch

New York-based style stars Olivia Palermo and Leighton Meester were both out for the Swarovski You Know You Want It: Style-Inspiration-Confidence book launch on November 5th.

Leighton went bold in a physcadelic print mini dress by Marios Schwab paired with black peep-toe ankle booties.

And Olivia, who many say is like a real-life version on Leighton's Blair Waldorf, wore one of her signature statement necklaces with a ruffled top, paired with black leather belt and leather Topshop skirt, plus some gorgeous studded zip-up heels.

Both Leighton and Olivia honored the night's host, Swarovski, wearing jewels from the brand. Olivia wore the hyacinth necklace from the brand's new Nature Reloaded Collection, and Leighton wore the jet black "Nirvana" ring, both available on-line at swarovski.com

Also at the event was Leighton's Gossip Girl co-star Nicole Fiscella, who donned all black and wore simple Christian Louboutin patent pumps.

Pics from Getty and leightonmeesterweb.com