In case you've been living under a rock (or, in Kate Middleton's case, quite a few), Prince William and his longtime love interest are officially headed for the long haul.

To seal the deal, Prince William proposed marriage with the late Princess Diana's 18-carat sapphire and diamond engagement ring, sparking a huge demand for sapphire rings and knockoffs alike across the Web and beyond.

Steal soon-to-be Princess Catherine's royal style with the Victoria Wieck 4.58ct Absolute™ and Created Sapphire Baguette Ring, $89.95, at hsn.com.

Celeb photo: MirrorPix/Splash News