It is a fluid phase, since the shear modulus and the Young's modulus vanish due to the dissociation of dislocations. It is an anisotropic phase, since there exists a director field with sixfold symmetry. The existence of the director field implies that an elastic modulus against drilling or torsion exists within the plane, that is usually called Frank's constant after Frederick C. Frank in analogy to liquid crystals. The ensemble becomes an isotropic liquid (and Frank's constant becomes zero) after the dissociation of disclinations at a higher temperature (or lower density). Therefore, the hexatic phase contains dislocations but no disclinations.