The Igneous Block Wall is a dark blood-red building-block with a quartered pattern on four sides, and with parallel lines on a smoother surface on two sides. Despite it's name, this block is not inflammable.
It can be crafted in your Crafting Menu (default key "Q") or at any Crafting Table in worlds created before R22 on September 16th 2015, after the recipe has been unlocked upon buying it in the Store as a part of the "Decorative Lava Pack" (as of R24 in November 2015).
To craft 8 (blocks of) Igneous Block Walls, you'll need (as of R24 in November 2015):
- 1x Melted Wax made of Beeswax in a Forge or looted from Wood Treasure Chests or Stone Treasure Chests
- 1 Iron Rod made of Iron Bars in a Processor or found in Iron Treasure Chests or in Diamond Treasure Chests
- 1 Stone Slab made of Stone, Limestone or Bedrock in a Processor
- 4 (blocks of) Igneous Rocks mined from the Lava layer, which requires at least an Iron Mining Cell
Despite it's name, this block fortunately is non-inflammable.