According to Memory-Alpha, Romulan transporter beams are supposed to dissolve in a green sparkle. Now we've all seen Klingon transporter beams and Cardassian ones too. But in all my time watching Star Trek, I'll be darned if I've ever seen an honest to goodness Romulan transporter beam. And I'm not including the Reman one in Nemesis.
Have you ever seen one?