Sucorolith

Sucoroliths are marine reefs created by colonies of virid zooid organisms called sucoaros. These zooid colonies create tube-like filter feeding structures, extracting nutrients from water and excreting particles of rock and debris around themselves for protection. Over time these create extensive rocky structures that can extend to just below or even above the waterline.

They are mainly found in warm shallow seas, where they can present a danger to shipping. The shallow northwestern coast of Anásthias has long stretches of sucorolith reefs, making the coast inaccessible to anything other than the shallowest fishing boats.

Inland sucorolith reefs were quarried in ancient times for corolstone, a light rock perforated with tube-like holes. Corolstone proved excellent for building, since it is lightweight yet strong, and a good insulator against heat and cold. Corolstone was particularly used by the ancient Issid, used to construct the grid pattern tower houses of cities like Toborr and Mezain.