Robuta

https://lifeartearth.blogspot.com/2024/09/a-19th-century-specimen-of-cotham.html A 19th century specimen of Cotham Marble, a Triassic microbialite Cotham Marble from near Bristol is far from uncommon, but old museum specimens of the material are rarely seen. One such 19th century specim... cotham marblecenturyspecimentriassic