What is the monoclinic crystal system in mineralogy ?
Monoclinic crystal system : definition
This system include about 21% of mineral species, the most common being micas, the majority of amphiboles and pyroxenes, gypsum, orthoclase, talc, chlorites, etc...
Certain monoclinic cells are said to be pseudocubic, pseudoquadratic, pseudo-orthorhombic or pseudohexagonal, when the cell parameters of a given monoclinic crystal approach those of these crystalline systems.