Just like the shell of a clam, a pearl is composed of calcium carbonate (mainly aragonite or a mixture of aragonite and calcite). in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes, known as baroque pearls, can occur.
Rimula is a genus of fungi in the Helotiales order. The relationship of this taxon to other taxa within the order is unknown (incertae sedis), and it has not yet been placed with certainty into any family. ^ Lumbsch TH, Huhndorf SM. (December 2007). Outline of Ascomycota â 2007.
What are diverticula? A gut diverticulum (singular) is an outpouching of the wall of the gut to form a sac. Diverticula (plural) may occur at any level from esophagus to colon. A true diverticulum includes all three layers of the gut; the lining mucosa, the muscularis, and the outer serosa. False diverticula are missing the muscularis and are therefore very thin walled. Colonic diverticula are typically false.