Silica began life as a liquid computer, an invention of the Coluan Vril Dox II better known as Brainiac 2.  He invented it as a symbiotic technological interface.  It allowed Dox to interface with remote computer systems, and it was also designed as a force field that could be extended out from Dox’s body.

When Dox went to Earth to capture the Omega Men, he learned that their mission was to acquire a mysterious Heartstone.  Left with too many avenues to pursue, Dox commanded Silica to leave him and search among the Spider Guild for the Heartstone itself.

The Omega Men also pursued the Spiders who stole the Heartstone, but when they finally caught up with the ship, they found it surrounded by a strange colony of small life forms.  This was Silica, which had since found the Heartstone and assumed its power.  Silica now had sentience but found itself confused as to a name and purpose.

Sensing a kindred spirit of another Heartstone in the Omega Men's Ryand'r, Silica reached out to him asking "What am I?"

He allowed it to interface with his mind and told Ryand'r of its origins.  With the wisdom of the Heartstone, Silica quickly knew intuitively the power and possessors of the four Heartstones.  It claimed that all that remained was a force to unite them.  When this happened, Lady Styx hoped to attain godhood and recreate the universe. She died in a Lady Styx battle. 
Silica's A.I. was duplicated on the planet Maltus by Brainiac 2 but she comes under attack by Astrild Storm-Daughter, a servant of Starro. The Omega Men are sent to destroy Silica before she can be manipulated by Starro. The Omega Men are successful in their mission but end up tasting Astrild's retribtution for their interference. Dox sends his REBELS recruit Wildfire to retrieve any viable remains of Silica so he can reproduce Silica. 
By rebuilding Silica, Dox hopes to regain control of his LEGION robots who are being manipulated by Starro. Unfortunately, Silica is unable to process Dox's request because her subprogram lacks a transmitter. Dox manages to get a transmitter from a Gordanian outpost and Silica is able to take back control of the LEGION robots. Dox instructs the robots to spread throughout Maltus' atmosphere then Silica activates a secret feature that the robots are equipped with.  
The robots create a force field that surrounds the planet which is similar to Brainiac's tactic for shrinking planets. With Starro trapped on Maltus and not going anywhere, Dox decides to destroy Silica by activating her self-destruct mechanism so no one can disrupt the force field or capture Silica for their own intentions. As cold blooded as Dox's decision was, Silica still professed her love for her creator when she was destroyed.