[1] Coined by the late Robert L. Folk, neomorphism encompasses the functions of both recrystallization and inversion, which are geological processes that deal primarily with rock reformation.
[2] The term "recrystallization" broadly refers to the many metamorphic processes that change the size and/or shape of crystal formations and preserve the chemical composition and mineralogy of the original mineral.
Polymorphs, to be clear, are minerals that differ from one another in their crystalline structures but are otherwise composed of identical quantities and types of elements.
As with any change in mineral structure, the alteration of polymorphs occurs most often in environments characterized by certain optimal temperatures and pressure levels.
Being similar to wet polymorphic transformations, recrystallization by replacement occurs on a variety of minerals, including chert, pyrite, hematite, apatite, anhydrite, and dolomite, among others.
Porphyroid neomorphism occurs when a small number of large crystals form in the area of static groundmasses, which are—as the name implies—areas of the ground that are characterized by relatively insignificant and unsubstantial metamorphic changes.
[5] Neomorphism is considered degrading when the recrystallization process is accompanied by a net decrease in the size of any affected crystal formation(s).