A maraji crystal was a controlled addictive substance illegal in the Cardassian Union. According to Quark, Cardassians didn't like the crystals (or possibly their effects) and Bajorans were too poor to buy them. In 2366, a spy for the Romulans, named Livara, was reportedly peddling maraji crystals on Terok Nor. Odo was investigating Livara's actions, and discovered that Livara had tried to sell the crystals to Quark.