Note the three equal axes running perpendicular to each other within a cube shape.

The six points of the octahedral crystal lie in the center of each square side of a cube, thus being named the cubic system.

The isometric crystal system consists of three equallength axes perpendicular to each other. Even though a typical diamond crystal is not cube-shaped it always falls into that isometric pattern. Many odd shapes and growths occur, being due to slightly non-uniform and changing crystallization conditions deep underground. It is part of the diamond cutter’s challenge to decipher and unravel this complex structure which can be very ambiguous. Later in the course we will discuss diamond cutting in detail, as well as the significance of how that relates to buying and selling.