Hilary duff and engagement ring

Um, Hil, you can't keep that big of a rock under wraps. Photo: Bauer Griffin | Fame Pictures (Inset)

Hilary Duff may be ready to say "I do," but she doesn't appear as ready to show off her new (and giant) engagement ring.

Duff was spotted with fiance/hockey player Mike Comrie at the Maui, Hawaii airport on Feb. 20 trying to hide her huge engagement ring from the paparazzi.

But her attempts to mask the bling bling behind a straw fedora fell short.

Duff, 22, and Comrie, 29, got engaged over the weekend during a romantic getaway. The singer-actress-designer was seen on the balcony of the Four Seasons Resort at Wailea admiring (and even photographing) her huge rock from the NHL player. And there's a lot to admire.

Our friends over at the Diamond Information Center estimate that the hockey star popped the question with a 14-carat radiant cut diamond with diamond side stones, and estimate its price tag at $500,000.

Guess Comrie really knows a thing or two about the ice!

Duff's rep told Us Weekly, "after having been together for over two years, they are very excited to share this happy news."

How does Duff's rock stack up in the celebrity diamond bling arena? Take a look at our engagement ring gallery to find out.