The angle between equivalent pairs of faces on different crystals of the same substance are always equal (at the same temperature and pressure)
What is Steno's Law (Law of Constancy of Interfacial Angles)?
200
NaAlSi3O8
What is Albite?
200
Enstatite (ortho-pyroxene)
What is MgSiO3?
200
Polymerized sheets of silica tetrahedra; WB2-3 Z4 O10(OH)2; Mica
What are Phyllosilicates?
200
Tiny pieces of a mineral of constant size that could be stacked to form the mineral OR the smallest part of the atomic lattice structure that possesses the chemistry and geometry of the mineral as a whole
What is Fundamental Polyhedra (unit cell)?
300
Muscovite
What is K(Al2)(AlSi3O10)(OH)2?
300
(Mg,Fe)7Si8O22(OH)2
What is ortho-amphibole?
300
Chain Silicates; ABZ2O6; eg. Pyroxenes and Amphiboles
What are inosilicates?
300
A simple mathematical relation exists between all planes that are possible faces on crystals of the same substance