A vintage wristwatch could become the world's most expensive Rolex ever sold at auction.
The 1971 Rolex Daytona Reference 6265 crafted in 18-karat white gold is the only one of its kind and considered to be so rare it's been nicknamed "The Unicorn."
Kevin O'Leary, star of "Shark Tank" and an avid watch collector, was given VIP access at Phillips auction house in New York to try on the iconic Rolex. O'Leary's initial reaction: "It's gorgeous."
"It is truly a holy grail piece … the only manually wound, vintage Rolex Daytona made in white gold," said Paul Boutros of Phillips in Association with Bacs & Russo.
Made in 1970 and then sold to an important German retailer the following year, Phillips told CNBC that at the time, the watch was probably the most extravagant model of the Daytona series ever created by the luxury watchmaker. The vast majority of Daytonas from this era were crafted in stainless steel.
The Unicorn's existence was legendary and few people in the industry had even known about it until it was revealed in 2013 that famed collector John Goldberger had acquired the watch.
"The world's jaw collectively dropped when they knew, … and we are absolutely thrilled to have the opportunity to auction it," said Boutros.
Phillips hopes to sell the timepiece for more than $3 million when it hits the auction block Saturday in Geneva.
"I'm probably one of the only people on Earth to put this on their wrist," O'Leary said, after trying on the substantial white gold Cosmograph with black dial. "This watch is magic."
Phillips hopes the first time this historic watch will be unveiled to the public will cement its status as one of the most important and expensive Rolex watches.
The auction house is still riding the momentum from its previous sales of Rolex watches that blew past estimates and shattered world records. Its sales have included the "Bao Dai" Rolex, which sold for $5 million last May, and more recently, a stainless steel Rolex Daytona wristwatch that was previously owned by Oscar-winning actor Paul Newman, which was estimated to sell in excess of $1 million. However, when the hammer dropped on Newman's timepiece in October, a whopping $17.8 million was spent to take it home.
The Paul Newman Daytona holds the record for the most expensive wristwatch ever sold at auction.
As for the Unicorn, Goldberger has decided to part ways with the timepiece in an effort to raise money and help others in need. All of the proceeds from the sale will benefit the charity Children Action.
— For more VIP access to high-end luxury check out CNBC's "Secret Lives of the Super Rich" on demand on CNBC and Apple TV.
Disclosure: CNBC owns the exclusive off-network cable rights to "Shark Tank."