Though Scots have a wonderful way with expressions and a great sense of humour, I'm pretty sure the one who first came up with "pure dead brilliant" to describe something fabulous were not contemplating death. But the expression fits perfectly to memorial diamonds.
Yes, Virginia, technology has moved forward and lockets of hair of a dear departed are passé. Get your hair or your ashes turned into a diamond. (no joking, it's a real business as the innovative first company to offer this unique product LifeGem has been joined by others) Forget the complications and uncertainty of reincarnation. Since diamonds are forever you can be present forever.
It's convenient for the living too. No messy ashes that could spill. No having to visit a far away grave, the loved one is ever present on your finger. Just give him or her a wee affectionate rub once in a while. And it's very discreet too, unless you want to brag how the person was a cut above the rest. Not only that, but one person can easily be used to make several diamonds - very convenient for each member of the family to get their very own piece of grand-dad.
Since any dead thing made of carbon can be turned into a diamond, consider also the mixing & matching possibilities - gran and grand-dad united forever, mom and her favourite cat etc.
Perhaps the only downside is the obvious one mentioned by lawyer Ian Hull, on whose blog Toronto Estate Law I found this idea. You could lose the diamond! (Sure hope there weren't any amongst the gigantic heist today at Brussels airport).