Silicate is a native resource, one mined from bodies rather than made: rock. It is found in every tier, and is second only to iron in the Hub, Relay and Static. A Smelter melts it into glass, which leads to boards and processors; a Mixer makes it into concrete for large builds; and fired with oxygen it becomes ceramic.
The Outpost and the Workshop are built from raw iron and silicate. Silicate is light next to the metals, so in a molten body it rises toward the surface while iron and copper sink.