Well, since every particle has its antimatter counterpart, therefore one can think about making anti hydrogen which is simply an atom comprised of a positron circulating an antiproton. And minute quantities HAS been produced in atom smasher labs. The first was in CERN.
Theoretically, making antielements from antiprotons, antielectrons and antineutrons is by all means possible.
In fact, anti-chemistry, anti-human, anti-galaxy or even anti-universe can exist.
So next time, if you see aliens descending in front of your lawn, throw a ball to he/she/it first. If that thing didn’t explode, you can take it to your leader safely.
Naturally, thinking of keeping antimatter in your pocket is suicide, because any contact with matter will result in an explosion. So, how do you store it?
The logical way to store it is using a magnetic hollow “doughnut”. (mathematical name - Torus)
First, we strip the antiatom from its positrons. Then it is electrically charged – called an anti-ion.
Then, we hurl the anti-ion inside a vacuumed hollow doughnut that has an intense magnetic field piercing through it perpendicularly. The magnetic field will deflect the path of the particle into a circular track. And the anti-ion is trapped inside!