zirconoid

Century Dictionary and Cyclopedia

1. n. In crystallography, a double eight-sided pyramid belonging to the tetragonal system: so called because it is a common form with zircon.

Wiktionary

1. n. crystallography A double eight-sided pyramid, a form common with tetragonal crystals; — so called because this form often occurs in crystals of zircon.

GNU Webster's 1913

1. n. (Crystallog.) A double eight-sided pyramid, a form common with tetragonal crystals; -- so called because this form often occurs in crystals of zircon.