"...a combination of two bisphenoids (P and P'), two bipyramids of the second order (b and c), and the basal pinacoid (a)." -The Encyclopedia Britannica 1910

Crystal of Chalcopyrite

"...a combination of two bisphenoids (P and P'), two bipyramids of the second order (b and c), and the…

An example of sphenoidal crystallization is Iron-Copper-Sulfide (FeS_2_Cu), also known as chalcopyrite.

Sphenoidal Crystallization

An example of sphenoidal crystallization is Iron-Copper-Sulfide (FeS_2_Cu), also known as chalcopyrite.