Metamorphic Reactions: Kinetics, Textures, and Deformation is the fourth in a series of books published under the series title Advances in Physical Geochemistry. The book is divided into three parts. The first contains five papers dealing with reaction kinetics and their effects on metamorphic assemblages. The opening paper, by M.A. Carpenter and A.P. Putnis, discusses the effects that cation order/disorder and metastable crystallization might have on the interpretation of mineral assemblages. This is followed by a discussion of the kinetics of metamorphic reactions (D.C. Rubie and A.B. Thompson) that summarizes a wide range of experimental and theoretical studies on mineral nucleation and growth rates.