Allotropy, or allotropism, is the quality which an element often has of appearing under various forms, with different properties.
"An Introduction to Chemical Science"
R.P. Williams
This property is spoken of by chemists as allotropism.
"Creation and Its Records"
B.H. Baden-Powell
Perhaps they have not studied the mystery of allotropism in the emotions of the human heart.
"The Complete PG Works of Oliver Wendell Holmes, Sr."
Oliver Wendell Holmes, Sr. (The Physician and Poet not the Jurist)