Defects in Synthetic Quartz Crystals

A an imperfections in the structure of a crystal can be classified into the following groups:

Point defects can be missing atoms, called vacancies, interstitial atoms, substituted, or vicarious, atoms, or combinations of these usually occurring in pairs.

Line defects, which extend along straight or curved lines in a crystal and are usually composed of edge dislocations and screw dislocations.

Plane defects, which may extend along truly plane or along curved surfaces within a crystal. These include small-angle boundaries and other surfaces marking discontinuities in a crystal's periodicity.

Volume defects, which extend throughout small volumes in a crystal, for example, occluded voids, large clusters of point defects, exsolved precipitates, and other kinds of inclusions.

The graphic at the left shows an edge location in a cubic crystal structure. You can see there is an extra plane of atoms, ending at an edge extending into the crystal structure.

Updated: 11/15/2010