Code Name : Red Flagstone
This Bronis is another kind of Lava stone or Basalt; and just like andesit, Bronis is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet.
but for certain exposure to the local atmosphere/weather the color resulted may vary, such as this Bronis. Unweathered lavastone is black or grey, and it is mostly perforated, a bit different from this Bronis.