Reidite
The high-pressure polymorph of zircon — a fingerprint of meteorite impact.
Intro adapted from Wikipedia (CC BY-SA).
Reidite is an IMA-recognized mineral species in the silicate class, with the chemical formula Zr(SiO₄).
It crystallizes in the tetragonal crystal system (space group I4_1/a).
Key properties: Mohs hardness 7.5; specific gravity 5.2; White streak; Adamantine luster; optically uniaxial.
IMA symbol Rei, IMA status: approved, named in 2001.
Epitaxially oriented in shock-metamorphosed zircons in an impact ejecta layer in marine sediment on the upper continental slope; detrital in clastic sedimentary rocks.
It is found associated with Impact glass (tektites), shocked quartz and feldspar with multiple sets of planar deformation features, coesite, stishovite.
The mineral was named to honor Alan F. Reid who first produced this phase in the laboratory.