Crystalline materials (mainly metals and alloys, but also stoichiometric salts and other materials) are made up of solid regions of ordered matter (atoms placed in one of a number of ordered formations called Bravais lattices). These regions are known as crystals. A perfect crystal is one that contains no point, linear, or planar imperfections. There are a wide variety of crystallographic defects.
The hypothetical concept of a perfect crystal is important in the basic formulation of the laws of thermodynamics.
In crystallography, the phrase 'perfect crystal' can be used to mean "no line or planar defects", as it is difficult to measure small quantities of point defects in an otherwise defect-free crystal.
Imperfections are created due to gravity. In space and in zero gravity environments perfect crystals can be created as on the International Space Station.
Famous quotes containing the words perfect and/or crystal:
“Strange that so few ever come to the woods to see how the pine lives and grows and spires, lifting its evergreen arms to the light,—to see its perfect success; but most are content to behold it in the shape of many broad boards brought to market, and deem that its true success! But the pine is no more lumber than man is, and to be made into boards and houses is no more its true and highest use than the truest use of a man is to be cut down and made into manure.”
—Henry David Thoreau (1817–1862)
“But the thing that I saw in your face
No power can disinherit:
No bomb that ever burst
Shatters the crystal spirit.”
—George Orwell (1903–1950)