GENERAL GEOLOGY

Detailed explanation-1: -All crystals of the isometric system possess four 3-fold axes of symmetry, each of which proceeds diagonally from corner to corner through the centre of the cubic unit cell. It is the most symmetrical system possible in three dimensional space. The isometric crystal system has the following forms: Cube.

Detailed explanation-2: -There are six (6) elements of symmetry in crystals: a Center of Symmetry, an Axis of Symmetry, a Plane of Symmetry, an Axis of Rotatory Inversion, a Screw-axis of Symmetry, and a Glide-plane of Symmetry.

Detailed explanation-3: -Symmetry elements are mirror planes, glide planes, rotation axes, screw axes, rotoinversion axes and inversion centres.

Detailed explanation-4: -Crystals have high symmetry, all having four 3-fold or four 3 axes. Some have three 4-fold axes as well, and some have 2-fold axes or mirror planes. Cubes and octahedra are examples of forms belonging to the cubic system, but other forms belong to the cubic system, too.

Detailed explanation-5: -Cubic or Isometric system: The crystals belonging to this system have three equal and mutually perpendicular axes which have been designated as a 1, a 2 and a 3 of equal length ( Fig. 1.1a). Crystals possess four triad axes of symmetry (4 iii ).