In Brief
There are more black holes than just the super scary world destroying supermassive black holes of science-fiction nightmares. There are even microscopic black holes in existence and the Large Hadron Collider can even produce them.

Black holes are notorious for their strange, somewhat counter-intuitive, nature. However, not all are created equal. For instance, we’ve seen many that outweigh billions of Suns, some that shouldn’t exist at all, and others that simply defy explanation. The strangest type theorized to exist is the micro (or primordial) black hole. As the name suggests, they are very, very, very small (microscopic, even), and quite unstable.

Since the strength of a black hole technically hinges on its size (deciding the boundary of its event horizon, or the so-called point of no return), could we possibly put one of them in our pocket without consequence (or at all)?

As a side note, physicists have suggested that the Large Hadron Collider could theoretically create micro back holes. In the case that it did, a baby black hole still wouldn’t do any damage, as it would take well over the universe’s current age for one to consume a milligram of matter. By that time, it would have evaporated into nothingness anyway.