DC Comics. Blackrock is a recurring enemy of Superman first appearing in Action Comics #458 (April 1976). Blackrock was the creation of Dr. Peter Silverstone in an attempt to increase ratings for the United Broadcasting television network. Silverstone hypnotized UB President Sam Tanner and later Tanner's nephew, Les Vegas, to fill the role. A third Blackrock (an energy construct) was created by Tanner's command not much later. Eventually Silverstone assumed the mantle of Blackrock himself, using a powerful stone that could metabolize electromagnetic energy into energy to achieve flight, energy blasts and superhuman strength, and fought Superman several times. This rock, while a technological artifact, has the appearance of a polished gem that is as black as coal. It was appropriately dubbed the Blackrock. The Post-Crisis version was stated (in Batman/Superman adventures) to be a symbiotic alien life form, rather than a creation of Dr. Silverstone. Its appearance and abilities are approximately the same. Silverstone is the only Pre-Crisis user of the stone that has been mentioned in Post-Crisis continuity. Overuse of the Blackrock's powers blinded Silverstone and left him insane. He was found sitting muttering to himself and watching constant television shows in an apartment owned by an ex-convict named Samuel Benjamin, who beat Silverstone to death with the Blackrock and took it for himself. Despite its power, his inexperience with the Blackrock led to his defeat and Superman took the stone and threw it towards the Sun. A short time later, Alexander Luthor Jr., disguised as Lex Luthor, dispatched Bizarro to retrieve the Blackrock from the Sun before passing it on to a South American woman named Lucia, a drug smuggler and revolutionary who had been jailed by Superman before. Her intense feelings of hatred towards the Man of Steel matched those of the Blackrock and she proved particularly adept in using it. However, her skills were not enough to defeat Superman and the Blackrock withdrew into itself. It was eventually shown that the Blackrock had been kept by Superman, who locked it away in his Fortress of Solitude. The Blackrock escaped and bonded with Plastic Man. Shortly after, the Blackrock was removed from Plastic Man and found its way into the hands of Batman, who shortly afterwards decided he needed its powers to help him stop a currently-rampaging Superman (Superman had fallen under the influence of Despero as he attempted to turn Earth's alien superheroes against humans).