The Structure and Properties of Engineering Materials
Enter
The Solid State, however, kept its grains
Of Microstructure coarsely veiled until
X-ray diffraction pierced the Crystal Planes
That roofed the giddy Dance, the taut Quadrille
Where Silicon and Carbon Atoms will
Link Valencies, four-figured, hand in hand
With common Ions and Rare Earths to fill
The lattices of Matter, Glass or Sand
With tiny Excitations, quantitatively grand.

The Metals, lustrous Monarchs of the Cave,
Are ductile and conductive and opaque
Because each Atom generously gave
Its own Electron to a mutual Stake,
A Pool that acts as Bond. The Ions take
The stacking shapes of Spheres, and slip and flow
When pressed or dented; thusly Metals make 
A better Paper Clip than a Window,
Are vulnerable to Shear, and, heated, brightly glow.

From: John Updike "The Dance of the Solids," (1969)

Photograph: Charge density waves in TaS2 , Coleman and Slough
University of Virginia. Scientific American, April 1994