This book explores the elastic-anisotropic properties of rocks from the Matert suite of the Pechenga complex, the Kola superdeep well (SG-3), the Finnish Outokumpu well, massifs in the vicinity of the Tuloma River and Lake Chudzyavr, and xenoliths from the explosion pipe (Elovy Island). It shows that velocity and density increase from prehnite-pumpelliite to granulite facies, while the anisotropy of rocks also increases with the deepening of the degree of metamorphic transformations. The book also details an acoustopolariscope that can be used not only to determine elastic properties of rock samples, but to control anisotropic alloys, plastics, ceramics, natural minerals, and gemstones.