Ashlee Simpson's fiancé wanted to propose with a ''unique'' ring.

The singer's beau Evan Ross - who popped the question on a New Year's trip to Hawaii - asked L.A. jeweller Neil Lane to design a custom-made diamond sparkler for the occasion.

During a visit to Neil's offices, the hunky actor fell in love with a vintage ring with a marquise-cut diamond surrounded by small rubies.

The jeweller-to-the-stars explained to People magazine: ''Evan was really, really sweet and he was looking for something beautiful, a unique ring that said everything: love, romance, beauty, character. He didn't want anything traditional.

''When he saw it, his eyes widened and that was it. But that was only the beginning.''

Evan, who is Diana Ross' son, worked closely with Neil to give the ring a more modern twist, transforming it into a one-of-a-kind five-carat ring with 140 white diamonds and small rubies.

Neil added: ''His taste level is exquisite and he wanted to make sure it was a perfect ring for his love ... Evan was blown away when he saw it!

''It was non-stop until the last minute when Evan picked up the ring last Friday, but it was worth it. It's one of the most beautiful rings I've ever done.''