Of or denoting a crystal system or three-dimensional geometric arrangement having three axes at right angles, two of them equal.
- ‘Zircon (variety cyrtolite) commonly forms curved tetragonal crystals that radiate from a base of biotite crystals and terminate in adjacent feldspar.’
- ‘Superb, equant tetragonal crystals occur on quartz in the junction pockets.’
- ‘Furthermore, we see that the molecular rows along the a axes are in perfect alignment with the underlying layers, as one would expect for the tetragonal lattice of the CO-HbC crystals.’
- ‘Small, black, tetragonal anatase crystals associated with rutile were found on microcline by Kile.’
- ‘Rutile is a tetragonal mineral famous for its variety of crystal habits and twinning.’
- ‘Xenotime crystals exhibit tetragonal prisms, dipyramids, and pinacoids, whereas zircon may exhibit first- and second-order tetragonal prisms, dipyramids, and pinacoids.’
- ‘Narsarsukite is another tetragonal mineral that can show a tetragonal prismatic habit, particularly when it develops in open cavities.’
- ‘The crystals are stepped tetragonal pyramids (somewhat resembling anatase) associated with chrysocolla.’
- ‘The crystals are typically tetragonal dipyramids with pinacoids.’
Late 16th century: via late Latin from Greek tetragōnon (neuter of tetragōnos four-angled) + -al.