Nicole Richie Engagement Ring

Nicole Richie shows off her rock on the way to David Letterman. Photo: DISCIULLO/bauergriffinonline.com | Ring Inset: T/X17online.com

First came love. Then came babies. And, now, after three years together, comes one really big diamond ring.

We're talking huge. Nicole Richie likes her accessories to be oversized, and, apparently, that extends to her taste in engagement rings.

"This ring is classic with a modern twist. Classic because it contains a brilliant cut center stone (approximately 3-4 carats) set in platinum, but the pave diamonds surrounding the center stone makes it modern. I would estimate the ring's value between $60,000 - $85,000.

"This diamond is set in platinum so it makes the diamond sparkle brighter. Also, Nicole won't have to worry about the large diamond falling out since platinum settings hold stones more securely than other metals," says jewelry and style expert Michael O'Connor.

The reality star turned designer, 28, confirmed her engagement to Good Charlotte's Joel Madden, 30, while taping an episode of "Late Show with David Letterman" last night (it's set to air Friday).

As did Madden on his Twitter page: "Yep, I'm engaged," he tweeted. "Very happy. Yeah we've been engaged for a while so your [sic] all kind of late on that. But thanks for the hoopla all the same." The tweets have since been removed.

The parents of Harlow Winter Kate Madden, 2, and Sparrow James Midnight Madden, 5 months, are planning a summer wedding, the Daily Mail reports.

Let the battle over whose dress she'll wear begin.

Then again, maybe Richie will just design it herself.

Plus, check out more celebrity engagement rings to see where Nicole Richie's falls, bling-wise.