Some unexpected phenomena observed in metallurgical studies are discussed. These phenomena include cruciform pattern formation, flat shuriken shape formation, whisker formation, solid state amorphization, woven structure formation and liquation. Cruciform patterns are found in the Sn/Te reaction couples reacted at 250℃ and in the Sn/Co couples reacted at 200°C. Instead of forming cruciform patterns, flat shuriken shape phases are observed at reentrant corners. Whiskers of pure Ag as long as 10 cm are found in Ag-In-Se alloys. Striations and faceted microstructures are observed. Similarly, Ag and Cu whiskers are observed in the annealed Ag-Cu-Te alloys with different compositions. In the Sn/Ni–7.0wt.%V reaction at 200℃, solid state amorphization reaction occurs and an amorphous T phase layer is formed. Peculiar woven microstructure is observed in the Sn-3.0 at.%Co-77.0 at.% Cu. The formation mechanism is understood by directionally solidified samples. Liquation observed in various kinds of solid/solid reactions are reported and analyzed.