Credit: MAC/Fame Pictures

Reese Witherspoon has some mega-bling to match her mega-watt smile!

The 34-year-old How Do You Know actress accepted a stunning 4 carat Ashoka cut diamond engagement ring from CAA agent Jim Toth. ( was the first to announce the couple's "happy" engagement.)

Toth, 40, worked with jeweler William Goldberg to design the perfect sparkler for his bride-to-be. Set on a pave diamond-and-platinum band, Goldberg says Toth was drawn to the rarity of the Ashoka diamond, particularly with its 62 displayed facets and rounded corners.

"Jim wants it to come from him and for it to be completely unique," a source told Us in November.

According to Goldberg, less than 10% of rough diamonds each year have the potential to become Ashoka cut diamonds, making it "the only choice" for a star like Witherspoon.