Examples from the Web for tetragonal
It consists of tin dioxide, or stannic oxide (SnO2), and crystallizes in the tetragonal system.
A silicate of zirconium usually crystallized in the tetragonal system as simple four-sided prisms capped by four-sided pyramids.Geology|William J. Miller
Optically uniaxial crystals—corresponding with the tetragonal and hexagonal systems.
Apophyllite always occurs as distinct crystals, which belong to the tetragonal system.
Though closely resembling the tetragonal torbernite in form, it crystallizes in the orthorhombic system and is optically biaxial.