Both royal weddings and engagement rings are black-hole topics for us. Once we start considering either, we could get lost forever. So you can imagine, as we contemplated Europe's royal engagement rings this morning, how long it was before we came up for air. (Hint: HOURS.) Today, part one of what we found: the engagement rings of the Belgian, British, Danish, and Dutch royal families. So. Many. Rings—many that you've probably never seen before. Belgian Royal Family The head of the Belgian…