This paper reviews the phenomenon of crystallization by particle attachment (CPA) in synthetic, biogenic, and geologic environments. Traditional crystal growth models, based on monomer-by-monomer addition, have limitations in explaining certain phenomena such as the formation of amorphous phases at low concentrations and irregular crystal morphologies. CPA involves the addition and attachment of particles ranging from multi-ion complexes to fully formed nanoparticles, leading to diverse crystal structures and properties. The review discusses the thermodynamic and kinetic factors influencing CPA, including the interplay of free-energy landscapes and reaction dynamics. It highlights the importance of surface energy, precursor phases, and extrinsic factors such as surfaces, impurities, and confinement in shaping crystallization pathways. The paper also explores the implications of CPA in various fields, including nanomaterials design, environmental remediation, and climate reconstruction. Despite significant progress, many aspects of CPA remain poorly understood, and the authors emphasize the need for multidisciplinary efforts to develop a comprehensive and predictive understanding of this process.This paper reviews the phenomenon of crystallization by particle attachment (CPA) in synthetic, biogenic, and geologic environments. Traditional crystal growth models, based on monomer-by-monomer addition, have limitations in explaining certain phenomena such as the formation of amorphous phases at low concentrations and irregular crystal morphologies. CPA involves the addition and attachment of particles ranging from multi-ion complexes to fully formed nanoparticles, leading to diverse crystal structures and properties. The review discusses the thermodynamic and kinetic factors influencing CPA, including the interplay of free-energy landscapes and reaction dynamics. It highlights the importance of surface energy, precursor phases, and extrinsic factors such as surfaces, impurities, and confinement in shaping crystallization pathways. The paper also explores the implications of CPA in various fields, including nanomaterials design, environmental remediation, and climate reconstruction. Despite significant progress, many aspects of CPA remain poorly understood, and the authors emphasize the need for multidisciplinary efforts to develop a comprehensive and predictive understanding of this process.