Some science behind the scenes

Piezoelectric crystals

Piezoelectricity is the charge which accumulates in certain solid materials (notably crystals, certain ceramics, and biological matter such as bone, DNA and various proteins) in response to applied mechanical stress.

Of the thirty-two crystal classes, twenty-one are non-centrosymmetric (not having a centre of symmetry), and of these, twenty exhibit direct piezoelectricity.  For example

  • Berlinite (AlPO4), a rare phosphate mineral that is structurally identical to quartz
  • Cane sugar
  • Quartz
  • Rochelle salt
  • Topaz
  • Tourmaline-group minerals

 

 

Observations

For iPad/iPhone users: tap letter twice to get list of items.