Credit: Denise Truscello/

Diamonds are Karina Smirnoff's best friend!

The Dancing With the Stars pro debuted her engagement ring from baseball player beau Brad Penny on Saturday at the fifth anniversary party for TAO in Las Vegas.

According to jewelry expert Michael O'Connor, the diamond sparkler is an estimated 4.5 carat princess cut, center stone diamond set on a platinum band that includes smaller channel-set princess cut diamonds.

Estimated price tag: $95,000!

"All these diamonds set into platinum provide maximum shimmer that's fit for a fairytale princess, and Karina has always liked romantic style rings," O'Connor, who once worked with Smirnoff for an awards show, tells

Smirnoff, 32, said Penny popped the question back in October after she Mike "The Situation" Sorrentino were voted off DWTS.

"I was in the middle of the show and had no clue what was cooking behind my back," she told Us, adding that the proposal happened at what she thought was a business meeting. "Even after Brad got down to one knee and opened the box with the ring, it still didn't register."

Added Smirnoff: "I'm the happiest I've ever been and Brad is the sole reason for that."