Kelly Clarkson is planning to design her fiance's wedding ring.The 'Stronger' singer - who announced her engagement on Saturday (15.12.12) just one day after her boyfriend of nine months Brandon Blackstock proposed - admitted she is looking forward to working with jewellery designer Johnathon Arndt, who helped create her new engagement ring. Sharing her dazzling yellow diamond with WhoSay, the 30-year-old star said: ''It's a yellow canary diamond with diamonds around it. Brandon designed it with Johnathon Arndt! They did an amazing job! I can't wait to make Brandon's ring with Johnathon as well!'' Kelly- who shot to fame after winning 'American Idol' in 2002 - shared her joy with her fans on Twitter, writing: ''I'm engaged!!!! I wanted y'all to know!! Happiest night of my life last night! I am so lucky and am with the greatest man ever.'' Kelly recently expressed her hopes that the couple would tie the knot even though they weren't yet engaged. Last month, she said: ''We are totally going to get married. We love each other. We are totally going to get married one day. ''I mean, he's got to put a ring on at some point. But I'll wait it out.'' Asked if she has thought about the kind of wedding she wants to have, the 'Since You've Been Gone' singer said: ''Honestly I've never been the girl to plan a wedding. We will totally, probably elope.'' Kelly's fiance - who is the son of her long-time manager Narvel Blackstock and the stepson of Reba McEntire - was previously married and has two children.