Where do you get refined siderium?

[Delta Kilo]

Where or how do you get refined siderium?

[Synthetic-Me]

im not in game and its been a min but i think you are referring to the crafting mat with the red crystal icon its later game mat and its pretty rare...you can buy high tier weapons and decon them for it but id suggest maxed decon on 6 engineers and stock pile the items untill you are ready to use 6 max decon engies so you can get the most mats from it