Not all resources in games are hard to come by. One of the most common elements present in almost every game is a form of currency. This has a low denomination, and you gather so much of it that you end up pouring it into tasks without much thought.
Cobalt (Co) is one of the resources in Starfield. It is very common and easy to come by. It is not used for a lot of things, making it something you shouldn't invest heavily into acquiring. Prioritize outpost construction for gathering rarer resources like Neon.
What Is Cobalt Used For
Cobalt only has one research project, and that should be the first thing you put your Cobalt towards. This is the Power Generation 1 research project. Once you have gotten that out of the way at your Research Lab, you can use your Industrial Workbench and Simple Fabricator to make any Isocentered Magnets you may need. There are also several Weapon Mods you may be interested in using this resource, such as the magnetic Rails, EM Charged Shot, Small Battery, or Standard Battery. It is best to go with the Standard Battery over the Small Battery.
Where To Get Cobalt
As previously stated, this resource is in a lot of places, more than 15% of the game's 1000 planets have the resource on them — 165 planets to be specific. Procyon IV and Akila are two planets you should be coming across for their story and resources, making them easy options for picking up some extra Cobalt.
Best Cobalt Farming Location
If you are not accumulating enough of this resource as you would like, you can just buy some. You can find this resource sold at the Mining League in Neon over on Planet Volii Alpha. Optionally, you can head to Midtown Minerals in Akila City over on planet Akila. Go to the vendor, buy up everything they have, and then rest for 48 hours to ensure enough time has passed for them to restock their wares. Head back over to the vendor and repeat this process until you have fully stocked up on all the Cobalt you could ever need.