Gamma Root is a rare substance in No Man's Sky obtained via Farming Gamma Weed plants at your Home Base or from the same plant in the wilds of planets with High Radiation.
It's primary uses are in the construction of Lubricant which then combined with Glass and then sold for exceptional amounts of units.
Where To Obtain
Here is a planet where Gamma Weed grows that only requires the first 2 Portal Glyphs to dial:
It is a moderately radio-active planet with a close resemblance to something you might find in a rotting biome.
Cool planet though prone to storms.