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.
A morula (Latin, morus: mulberry) is an early stage embryo consisting of cells (called blastomeres) in a solid ball contained within the zona pellucida.he morula is produced by a series of cleavage divisions of the early embryo, starting with the single-celled zygote. Once the embryo has divided into 16 cells, it begins to resemble a mulberry, hence the name morula (Latin, morus: mulberry).