Page 11 - ilovepdf_merged

freedom of growth. It prevents crystallization and all crystal faces may be
formed, missing or absent
Properties of Crystals

1- Crystal faces
These are the outer surfaces or planes that define the crystal. They are
usually flat and sometimes curved, as in some samples of Siderite and
diamond, and in a single crystal, either the faces are similar, as in the
crystal of halite, which crystallizes in the form of a cube similar to any
face in which the other faces or are not similar as in the crystallization of
the mineral galena. The crystal faces are the external expression of the
atomic structure, the faces usually grow in the levels that contain the
largest number of atoms, any metal has a fixed atomic arrangement and
therefore distinct crystal faces.

2- Crystal Edge:
It arises from the meeting of two adjacent faces or planes, and the edge is
parallel to the line on which the greatest number of atoms is located.