  Riemannian geometrical tools, such as Ricci collineations and Killing
symmetries, so often used in Einstein general theory of gravitation are here
applied to plasma physics to build magnetic surfaces from Einstein plasma
metrics used in tokamak devices. It is shown that the Killing symmetries are
constrains the Einstein magnetic surfaces while the Killing vectors are built
in terms of the displacement of the toroidal surface. The pressure is computed
by applying these constraints to the pressure equations in tokamaks. A method,
based on the sign of the only nontrivial constant Riemann curvature component,
is suggested to classify tearing instability. Throughout the computations two
approximations are considered: The first is the small toroidality and the other
is the small displacement of the magnetic surfaces as Einstein spaces.
