Here's what the wiki says about Omegon: There are no known locations yet for mining Omegon, and it cannot be found with a scanner.
It glows Purple and floats upon the ground.
However Directly underneath this statement the wiki also says: You can find Omegon ore on certain radioactive planets.
Create a hole with the Grenade launcher beneath the Omegon ore before extracting it because it often falls in two pieces and rolls down the mountains and even on flat grounds.
In this way you can mine it easier.
The wiki states that dismantling Cannon damage Theta or Beam impact Theta will also yield some Omegon.
Wiki Page
gaming.stackexchange.com/users/165316/Micoxion
As an addition to the existing answer: If you feed animals on a planet, they will usually "spawn" resources for you afterward, one of which can be omegon.
gaming.stackexchange.com/users/132706/Ken Bourassa
The Wiki now contains a picture of what it looks like:
It also states that Omegon spawns on radioactive planets and you cannot use a scanner to locate it: You can find Omegon ore on certain radioactive planets, but it cannot be found with a scanner.
gaming.stackexchange.com/users/163757/Timmy Jim
You can find Omegon on any planet by salvaging crashed ships and breaking technologies down into resources.
This goes for other valuable resources like Gravitino Balls, Dimension Matrix, Gold, Emeril, etc.
as well.
When you break techs down into resources, just go back to your original ship and take it back.
(so be sure you have parked it where you can find it again, because after you have accepted the new ship, there is no marker pointing back to your original ship) For this to work however, you need to be sufficiently far into the game in order for you to find ships with applicable technologies installed.
But if you need it to repair a tech on a ship, there is a good chance that crashed ships will have that tech too.
gaming.stackexchange.com/users/6454/Pete
I haven't seen Omegon myself and a quick google searched turned up nothing and neither does the wiki .
I have gotten it either buying it at space stations or by dismantling certain upgrades on crashed ships.
Precious tier ores like Omegon are noted with a green (!)
when scanning the planet.
gaming.stackexchange.com/users/37612/VanBuzzKill
I've been playing the game for some time now, and I have yet to stumble upon any Omegon.  I understand that it is rare, but are there particular environments/planets where it is more common?  I'm currently in need of it to repair one of technologies on my ship.  More so, what does it even look like so I can keep my eyes peeled?
Finding the rare element Omegon
gaming.stackexchange.com
<no-mans-sky>
gaming.stackexchange.com/questions/284456
gaming.stackexchange.com/users/163757/Timmy Jim
 There are no known locations yet for mining Omegon. It glows Purple and floats upon the ground. You can find it on any planet by salvaging crashed ships and breaking technologies down into resources. Omegon doesn't have known locations where it can be found, however radioactive areas seem to have some. It is purple and floats on the ground. Another way to get some is to salvage crashed ships and breaking down technologies.
Users provide information about Omegon