Because he doesn't really love you unless he gives you an ALL-DIAMOND RING, like this one from Shawish Jewelers of Geneva, Switzerland.
I'm sure they have both Chuck Berry and Pulp Fiction in the 24th century, and will totally get that reference.
For those of you who want the karat count in your diamond to match your maturity level.
A whole lotta trust going on in this relationship, you can tell...
When you wish upon a ring, makes no difference who you... dammit, that doesn't rhyme well!