Définition : overall repetitive or reflective pattern in the body of one individual of this taxon. eg: bilateral symmetry, rotational symmetry, radial symmetry
Définition : 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.
