X-Kryptonite (UE-43)

X-Kryptonite (X-K) is a radioactive mineral that creates Metahumans with Kryptonian powers.

Meteor Shower
When Kal-El's pod landed on Earth, there were meteor showers all over the planet which resulted in the remnants of Krypton to arrive on Earth, among those remnants were X-Kryptonite.

Search for X-Kryptonite
Years later, Tal-Rho, using the name "Morgan Edge", led a group of scientist to Saskatchewan to search for X-Kryptonite during another meteor shower.

Smallville
In 2020, Morgan Edge went to different cities including New Carthage, Granville and Hazel Green in search of X-Kryptonite as well as recruiting willing hosts for Kryptonians. Edge eventually settled in Smallville, where its citizens already adapted to the radiation of the mineral and allowed their bodies to not fight against the X-Kryptonite experiments. Edge later signed a partnership deal with the town in order to extract the mineral from the Shuster Mines while setting up a Young Executive Program to recruit hosts.

Trivia

 * X-Kryptonite contains the element Krypton.