Nacrite

Nacrite
Nacrite, "Frohe Hoffnung"-shaft, Wildental, Ore Mountains
General
CategoryPhyllosilicates
Kaolinite-serpentine group
Formula
(repeating unit)
Al2Si2O5(OH)4
IMA symbolNcr[1]
Strunz classification9.ED.05
Crystal systemMonoclinic
Crystal classDomatic (m)
(same H-M symbol)
Space groupCc
Identification
References[2][3]

Nacrite Al2Si2O5(OH)4 is a clay mineral that is polymorphous (or polytypic) with kaolinite. It crystallizes in the monoclinic system. X-ray diffraction analysis is required for positive identification.

Nacrite was first described in 1807 for an occurrence in Saxony, Germany. The name is from nacre in reference to the dull luster of the surface of nacrite masses scattering light with slight iridescences resembling those of the mother of pearls secreted by oysters.

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ Mindat Data sheet
  3. ^ Webmineral data