Definition: A group of hydrous aluminium phyllosilicate (phyllosilicates being a subgroup of silicate minerals) minerals (see clay minerals), that are typically less than 2micrometres in diameter. Clay consists of a variety of phyllosilicate minerals rich in silicon and aluminium oxides and hydroxides which include variable amounts of structural water.
Definition: An organism that feeds on mud or sand and shows little discrimination in the size or type of particles eaten. The sediment is ingested and any digestible organic material is assimilated as it passes through the alimentary canal.
