This bunny's got bling!

When Crystal Harris, 24, accepted an engagement proposal from her love, Hugh Hefner, 84, she got a sizable sparkler, too.

The 2009 Playmate of the Month showed it off on Twitter on Thursday. "For those of you who have been asking to see my ring here it is," she Tweeted. "My engagement ring from my love."

If diamonds are any indication of that love, then it's sizable. Jewelry expert Michael O'Connor tells that the ring appears to have a 3 1/2 carat brilliant-cut diamond set in platinum with micro pave diamonds along the band.

"The round center gives the ring a classic style, while micro pave makes it more modern and youthful," he tells Us.

O'Connor's estimated cost of the ring: $90,000.

Harris began dating Hefner in January 2009. Their marriage will be the third for the Playboy founder.