The following definitions on what constitutes a mineral were taken from several
different sources and are arranged by year:
"A mineral is an element or chemical compound that is normally
crystalline and that has been formed as a result of geological
processes" (Nickel, E. H., 1995).
"Minerals are naturally-occurring inorganic substances with a definite and
predictable chemical composition and physical properties." (O' Donoghue,
"A mineral is a naturally occurring homogeneous solid, inorganically formed, with a
definite chemical composition and an ordered atomic arrangement" (Mason, et al,
"These... minerals ...can be distinguished from one another by individual
characteristics that arise directly from the kinds of atoms they contain and the
arrangements these atoms make inside them" (Sinkankas, 1966).
"A mineral is a body produced by the processes of inorganic nature, having usually
a definite chemical composition and, if formed under favorable conditions, a certain
characteristic atomic structure which is expressed in its crystalline form and other
physical properties" (Dana & Ford, 1932).
"Every distinct chemical compound occurring in inorganic nature, having a definite
molecular structure or system of crystallization and well-defined physical properties,
constitutes a mineral species" (Brush & Penfield, 1898).