The Siltstone Wall is a cream-colored building-block with dark green fancy ornaments with golden frames that resemble flower petals.
On two of its sides the symbols on the block are spare, half-rhombic at the edges and corners of the block, while on the other four sides the petal-like symbols are dominant.
The block can be rotated by pressing and holding R and moving the mouse while holding the left mouse button.
Siltstone Walls can be crafted in your Crafting Menu (default key "q") after the crafting-recipe has been unlocked by
- mining Siltstone from the Stalactite layer underground with an Obsidian Mining Cell or better
- mining blocks of Mold from the Stalactite layer underground with a Stone Mining Cell or better
- crafting Bedrock Walls
- and crafting Limestone Walls
To craft 8 (blocks of) Siltstone Walls, you'll need (as of R44 in June 2017):
- 4 (blocks of) Stalactite from the Stalactite layer, mined with at least an Obsidian Mining Cell
- 1 (block of) Mold from the Stalactite layer, mined with at least a Stone Mining Cell
- 4 (blocks of) Siltstone from the Stalactite layer, mined with at least an Obsidian Mining Cell
- 1 Stone Rod made of Stone, Limestone or Bedrock in a Processor