Most efficient adaptive mesh methods employ only a few strategies,
including local mesh refinement (h-adaptation), movement of mesh nodes
(r-adaptation), and node reconnection (c-adaptation). Despite of
its simplicity, node reconnection is the least popular
of the three. However, using only node reconnection the discretization
error can be significantly reduced. In this paper, we
develop and numerically analyze a new c-adaptation algorithm for
mimetic finite difference discretizations of elliptic equations on
triangular meshes. Our algorithm is based on a new error indicator for
such discretizations, which can also be used for unstructured
general polygonal meshes. We demonstrate the efficiency of our
new algorithm with numerical examples.