Red matter
From Memory Alpha, the free Star Trek reference
(covers information from several alternate timelines)
Red matter is an unstable matter with distinct gravitational properties, specifically a propensity to condense into quantum singularities, first seen in the 24th century. Red matter must first be ignited for the condensation into a singularity to occur. Red matter is highly unstable and can easily be ignited by conventional methods such as heat or shock much like gun powder.
When a star went supernova and threatened the entire Milky Way Galaxy in 2387, Ambassador Spock used his spacecraft, the Jellyfish, to inject red matter into the star, creating an artificial black hole which devoured the star. Unfortunately, Spock was unable to complete his task before the supernova destroyed Romulus.
Both Spock and the Narada, commanded by Nero, were pulled into the black hole created by the red matter. The Narada would end up in the year 2233, where Nero drastically altered the timeline by destroying the USS Kelvin and killing George Kirk. Spock emerged from the black hole in 2258 of the alternate reality, where his ship was captured by Nero. Nero then used the red matter that was aboard the Jellyfish to create a black hole in the center of Vulcan, destroying the planet.
The Narada was ultimately destroyed when the Spock of that era rammed the Jellyfish into the Narada. The red matter that was aboard the Jellyfish ignited, creating a massive black hole which crushed the Narada before devouring it. (Star Trek)
[edit] Apocrypha
According to the Star Trek: Countdown prequel comic book, which details the events leading up to the destruction of Romulus, red matter is an artificial substance created by the Vulcan Science Academy. It is manufactured from decalithium, a rare isotope which the Narada was equipped to mine.
The novelization of 2009's Star Trek by Alan Dean Foster states that red matter's destructive properties are magnified by intense heat and pressurization that a star or a planetary core can provide.
The Path to 2409 on the Star Trek Online website states that the Vulcans had created Red Matter without the consultation or approval of Federation authorities, earning criticism from the board investigating the destruction of Romulus. In response the Vulcans promise to not conduct anymore Red Matter experiments and state that the entire supply was on Spock's ship when it vanished.
[edit] Background
In an interview with Star Trek Magazine, Scott Chambliss, production designer on Star Trek, said that the appearance of red matter as a "big red ball" was a reference to other productions that he has worked on with J. J. Abrams which also included red balls, including Alias and Mission: Impossible III. [1]
