\Al*lot"ro*pism\, Allotropy \Al*lot"ro*py\, n. [Gr.
? other + direction, way, ? to turn: cf. F. allotropie.]
(Chem.)
The property of existing in two or more conditions which are
distinct in their physical or chemical relations.
Note: Thus, carbon occurs crystallized in octahedrons and
      other related forms, in a state of extreme hardness, in
      the diamond; it occurs in hexagonal forms, and of
      little hardness, in black lead; and again occurs in a
      third form, with entire softness, in lampblack and
      charcoal. In some cases, one of these is peculiarly an
      active state, and the other a passive one. Thus, ozone
      is an active state of oxygen, and is distinct from
      ordinary oxygen, which is the element in its passive
      state.