Ice VI

Phase diagram of water
  • Can be formed from liquid water at 11 kbar by lowering the temperature to approx. -3 °C
  • Density: 1.31 g/cm3

Structural features

Crystal structure of Ice VI
  • Ice VI is a proton-disordered phase
  • it is composed of two independent interpenetrating networks of H-bonded water molecules (shown above in blue and red, respectively)
  • the main structural motif is a tricyclic, cage-like water hexamer, similar as in liquid water
A tricyclic water hexamer composed of four-membered rings
  • This motif is also found for the silicon atoms in the zeolite edingtonite, see here for comparison.
  • The respective topology of the underlying net is edi, a binodal (4,4)-c net with transitivity pqrs = 2343
  • Space group: P42/nmc (No. 137)
  • Crystal system: Tetragonal
  • Lattice parameters:
    • a = b = 6.116(1) Å, c = 5.689(1) Å
    • α = β = γ = 90°

Literature:

[1] W. F. Kuhs, J. L. Finney, C. Vettier and D. V. Bliss, Structure and hydrogen ordering in ices VI, VII and VIII by neutron powder diffraction. J. Chem. Phys. 1984, 81, 3612-3623.
DOI: 10.1063/1.448109

Here, you can download the CIF.

Atomistic structure figures were created with:

VESTA
K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,” J. Appl. Crystallogr.44, 1272-1276 (2011).

Pentlandite – the most important nickel ore

Pentlandite

  • Named after the Irish natural historian, J. B. Pentland (1797-1873)
  • Pentlandite is the most important nickel ore
  • Formula: (Fe,Ni)9S8
  • Space group: Fm-3m (No. 225)
  • Crystal system: cubic
  • Crystal class: m-3m
  • Lattice parameters: a = b = c = 10.1075(1) Å, α = β = γ = 90°

Picture by: John Sobolewski (JSS) – http://www.mindat.org/photo-192760.html, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=9578696


Crystal structure (click on the picture to download the VESTA file):

(K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,”J. Appl. Crystallogr., 44, 1272-1276 (2011).)

  • For both metal cation positions there is a complete disorder between Ni and Fe.
  • There are two distinct coordination environments; octahedrally coordinated metals at the center and all edge centers and tetrahedrally coordinated metals for the others.
  • Eight tetrahedra each form edge-connected Fe/Ni8(µ-S)6S8 motifs, that means cubes of metal ions with six face-capping and eight terminal S atom. If we take now these cubes and octahedra as building blocks they form a NaCl-like structure.
  • Fe/NiS4 tetrahedra (blue)
  • Fe/NiS6 octahedra (orange)
  • Fe (brown)
  • Ni (green)

For a 3D interactive version on sketchfab, see here:

https://skfb.ly/6UPTq

References:

[1] Tenailleau, C., Etschmann, B., Ibberson, R. M. & Pring, A.
A neutron powder diffraction study of Fe and Ni distributions in synthetic pentlandite and violarite using 60Ni isotope.
Am. Mineral. 91, 1442–1447 (2006)

[2] Stacey, T. E., Borg, C. K. H., Zavalij, P. J. & Rodriguez, E. E.
Magnetically stabilized Fe8(µ-S)6S8 clusters in Ba6Fe25S27.
Dalton Trans. 43, 14612–14624 (2014)

Textbook available

I’m very happy that the English edition of my book on #crystallography is finally available!

I know it is a bit expensive, but at least you get the eBook when you order the hardcover version.

You can order it here:

https://www.springer.com/us/book/9783030351090

On this page you can find some electronic supplementary materials, for instance CIF files of the crystal structures that are mentioned in the book, sheets for paper models of typical crystal shapes and some animations.

Atacamite and Hibbingite

Atacamite

  • Named after its type locality, the Atacama desert in Chile.
  • Atacamite is isostructural with Hibbingite [Fe2Cl(OH)3], and Kempite [Mn2Cl(OH)3]
  • In 2002 it was found out that the jaws of the marine bloodworm Glycera dibranchiata contain Atacamite.[1]
  • Atacamite is polymorphous with Botallackite and Clinoatacamite (both monoclinic).
  • Formula: Cu2Cl(OH)3
  • Space group: Pnma (No. 62)
  • Crystal system: orthorhombic
  • Crystal class: mmm
  • Lattice parameters: a = 6.030(2) Å, b =  6.865(2) Å, c = 9.120(2) Å, α = βγ = 90°

Picture: By Stefan Schorn – CC BY-SA 3.0
http://www.mineralienatlas.de/lexikon/index.php/Bildanzeige?pict=1081079762,
https://commons.wikimedia.org/w/index.php?curid=399210


Crystal structure[2] (click on the pictures to download the VESTA file):

(K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,” J. Appl. Crystallogr., 44, 1272-1276 (2011).)

  • CuO5Cl distorted octahedra (orange)
  • CuO4Cl2 distorted octahedra (blue)
  • Oxygen (red)
  • Chlorine (green)
  • Hydrogen (white)

For a 3D interactive version, see here:

https://skfb.ly/6QpQY

References:

[1] H.C. Lichtenegger, Th. Schöberl, M.H. Bartl, H. Waite, G.D. Stucky
Science 2002, 298, 389-392.
DOI: 10.1126/science.1075433

[2] J.B. Parise, B.G. Hyde
Acta Cryst. C 1986, 42, 1277-1280.
DOI: 10.1107/S0108270186092570


Hibbingite

  • Named after its type locality, the city of Hibbing, which was built on the rich iron ore of the Mesabi Iron Range. At the edge of the town is the largest open-pit iron mine in the world.
  • Hibbingite is isostructural with Atacamite [Cu2Cl(OH)3] and Kempite [Mn2Cl(OH)3]
  • Formula: Fe2Cl(OH)3
  • Space group: Pnma (No. 62)
  • Crystal system: orthorhombic
  • Crystal class: mmm
  • Lattice parameters: a = 6.3373(2) Å, b =  6.9892(2) Å, c = 9.3457(3) Å, α = βγ = 90°

Crystal structure (click on the pictures to download the VESTA file):

(K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,” J. Appl. Crystallogr., 44, 1272-1276 (2011).)

  • FeO5Cl distorted octahedra (green)
  • FeO4Cl2 distorted octahedra (brown)
  • Oxygen (red)
  • Chlorine (green)
  • Hydrogen (white)

For a 3D interactive version, see here:

https://skfb.ly/6QpRS

Reference:

N.V. Zubkova, I.V. Pekov, E.V. Sereda, V.O. Yapaskurt, D.Y. Pushcharovsky
Z. Kristallogr. 2019, 234 (6), 379-382.
DOI: 10.1515/zkri-2018-2124


 

Schoenfliesite

Schoenfliesite

  • Named in 1971 by George T. Faust and Waldemar T. Schaller in honor of Arthur Moritz Schoenflies ( 17 April 1853 – 27 May 1928) Professor of Mathematics, University of Frankfurt. Schoenflies’ researches in group theory and topology resulted in his proof of the 230 space groups.
  • Formula: MgSn(OH)
  • Space group: Pn-3 (No. 201)
  • Crystal system: cubic
  • Crystal class: m-3
  • Lattice parameters: a = b = c = 7.7449(4) Å, α = β = γ = 90°

Crystal structure (click on the picture to download the VESTA file):

(K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,”J. Appl. Crystallogr., 44, 1272-1276 (2011).)

  • MgO6 octahedra (orange)
  • SnO6 octahedra (blue-gray)
  • Hydrogen (white)

For a 3D interactive version on sketchfab, see here:

https://skfb.ly/6QpyS

Reference:

Description of Schoenfliesite, MgSn(OH)6, and Roxbyite, Cu1.72S, from a 1375 BC Shipwreck, and Rietveld Neutron-diffraction Refinement of Synthetic Schoenfliesite, Wickmanite, MnSn(OH)6, and Burtite, CaSn(OH)6
L.C. Basciano, R.C. Peterson, P.L. Roeder
The Canadian Mineralogist 1998, 36, 1203-1210.

Spangolite – A Pyroelectric Copper Sulfate Sheet Mineral

Spangolite

  • Named in honour of Norman Spang (1841–1922), a mineral collector from Pennsylvania, USA; for details, see here.
  • Spangolite is pyroelectric
  • Formula: Cu6Al(SO4)(OH)12Cl · 3 H2O
  • Space group: P31(No. 159)
  • Crystal system: trigonal
  • Crystal class: 3m
  • Lattice parameters: a = b = 8.254(4) Å, c = 14.354(8) Å, α = β = 90°, γ = 120°

Picture: Christian Rewitzer, CC BY-SA 3.0
https://commons.wikimedia.org/w/index.php?curid=14865917


Crystal structure (click on the picture to download the VESTA file):

(K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,”J. Appl. Crystallogr., 44, 1272-1276 (2011).)

  • CuO6 distorted octahedra (blue)
  • AlO6 octahedra (orange)
  • SOtetrahedra (yellow)
  • Oxygen (red)
  • Chlorine (green)
  • Hydrogen (white)

For a 3D interactive version on sketchfab, see here:

https://skfb.ly/6Q6U7

References:

[1] Spangolite
H. A. Miers
Mineralogical Magazine 1894, 10, 273-277

DOI: 10.1180/minmag.1894.010.48.02

[2] The Crystal Structure of Spangolite, a Complex Copper Sulfate Sheet Mineral
F.C. Hawthorne, M. Kimata, R.K. Eby
American Mineralogist 1993, 78 (5-6), 649-652.

Suzukiite – polymorphic to Bavsiite

Suzukiite

  • Named in honor of Jun Suzuki, a professor of mineralogy and petrology, at the Hokkaido University, Sapporo (Japan).
  • Suzukiite belongs to the inosilicates (chain silicates) and is polymorphic to Bavsiite, which is tetragonal.
  • Formula: BaVSi2O7
  • Space group: Cmcm (No. 63)
  • Crystal system: orthorhombic
  • Crystal class: mmm
  • Lattice parameters: a = 5.3546(16), b = 15.249(5) Å, c = 7.094(2) Å, α = β = γ = 90°

Picture: D. Nishio-Hamane – CC BY-NC-SA 2.0


Crystal structure (click on the picture to download the VESTA file):

(K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,”J. Appl. Crystallogr., 44, 1272-1276 (2011).)

 

  • BaO10 polyhedra (not shown as polyhedra, Ba green)
  • SiO4 tetrahedra (yellow)
  • VO5 square pyramids (purple)
  • Oxygen (red)

For a 3D interactive version on sketchfab, see here:

https://skfb.ly/6Q6GC

Reference:
Crystal Structure of Suzukiite from the Mogurazawa Mine, Gunma Prefecture, Japan,
M. Ito, S. Matsubara, K. Yokoyama, K. Momma, R. Miyawaki, I. Nakai, A. Kato
Journal of Mineralogical and Petrological Sciences 2014, 109, 222-227

DOI: 10.2465/jmps.140520

Bavsiite – A mineral containing Ba, V, Si,…

Bavsiite

  • Named for the constituting elements Barium, Vanadium and Silicon.
  • Bavsiite is polymorphic to Suzukiite, BaVSi2O7, which is orthorhombic.
  • Formula: Ba2V2O2[Si4O12]
  • Space group: I4/(No. 87)
  • Crystal system: tetragonal
  • Crystal class: 4/m
  • Lattice parameters: a = b = 7.043(1) Å, c = 11.444(2) Å, α = β = γ = 90°

Crystal structure (click on the picture to download the VESTA file):

(K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,”J. Appl. Crystallogr., 44, 1272-1276 (2011).)

  • BaO12 polyhedra (not shown as polyhedra, Ba green)
  • SiO4 tetraedra (yellow) building single four-rings
  • VO5 square pyramids (blue)
  • Oxygen (red)

For a 3D interactive version on sketchfab, see here:

https://skfb.ly/6PYVA

Reference:
Bavsiite, Ba2V2O2[Si4O12], mineral data and crystal structure
H.-P. Bojar, F. Walter, J. Baumgartner
Mineralogical Magazine 2019, 83, 821-827

DOI: 10.1180/mgm.2019.59

Wulfenite

Wulfenite

  • Named in honour of Franz Xavier Wulfen (1728–1805), Austrian–German Jesuit, who wrote a monograph on the lead ores of Bleiberg, Austria.
  • Wulfenite was voted “Mineral of the Year” in Austria in 2020.
  • In its pure form wulfenite is colorless; the often yellow to red colour is most probably due to trace amounts of chromium substituting Mo.
  • Formula: PbMoO4
  • Space group: I41/(No. 88)
  • Crystal system: tetragonal
  • Crystal class: 4/m
  • Lattice parameters: a = b = 5.434 Å, c = 12.107 Å, α = β = γ = 90°

Modified by CombineZP

Picture: Didier Descouens – CC BY-SA 4.0
https://commons.wikimedia.org/w/index.php?curid=12426342


Crystal structure (click on the picture to download the VESTA file):

(K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,”J. Appl. Crystallogr., 44, 1272-1276 (2011).)

  • PbO8 coordination environment
  • MoO4 tetrahedra (blue)
  • Pb (black)
  • Oxygen (red)

For a 3D interactive version on sketchfab, see here:

https://skfb.ly/6PW6U

Reference:
Natural wulfenite: structural refinement by single-crystal X-ray diffraction
C. Lugli, L. Medici, D. Saccardo,
Neues Jahrbuch fur Mineralogie, Monatshefte 1999, 6, 281-288

Vanadinite – the most important vanadium source

Vanadinite

  • Named for its vanadium content
  • Vanadinite is the most important source of vanadium and finds application as V2O5 in the famous contact process (production of sulfuric acid) and in alloys for chromium-vanadium steel (typically the content is below 0.2 %)
  • Formula: Pb5(VO4)3Cl
  • Space group: P63/(No. 176)
  • Crystal system: hexagonal
  • Crystal class: 6/m
  • Lattice parameters: a = b = 10.299(2) Å, c = 7.308(1) Å, α = β = 90°, γ = 120°

Picture: Didier Descouens – CC BY-SA 4.0
https://commons.wikimedia.org/w/index.php?curid=12436369


Crystal structure (click on the picture to download the VESTA file):

(K. Momma and F. Izumi, “VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data,”J. Appl. Crystallogr., 44, 1272-1276 (2011).)

  • PbO9 irregular polyhedra (black)
  • PbO7 capped trigonal prisms (blue)
  • VO4 tetrahedra (purple)
  • Oxygen (red)
  • Chlorine (green)

For a 3D interactive version on sketchfab, see here:

https://skfb.ly/6PT8q

Reference:
Crystal structure of vanadinite: refinement of anisotropic displacement parameters
F. Laufek et al.
J. Czech Geol. Soc. 2006, 51, 271-275

DOI: 10.3190/JCGS.999