Jewellery designer Dara Dubinet has designed a $27,000 black Chinese agate rock ring for Britney Spears to wear to the Grammy Awards in February.

Dubinet started work on the huge gem after she spotted Spears wearing a Tourmaline ring she had created and sent to the pop star when she appeared on U.S. morning show Good Morning America on her 27th birthday in December.

The designer tells Life + Style magazine she was told Spears "loved" her birthday gift.

And a source tells the publication, "She's worn it several times, She says it has a positive energy, and it just makes her smile."