Abstract
Structural and volume compressibility data for low albite were obtained by single-crystal X-ray diffraction methods at pressures up to ~4 GPa. The bulk modulus was determined to be 54(1) GPa, with a pressure derivative of 6(1). Intensity data were collected, and structures were refined at 0.00, 0.44, 1.22, 2.68, and 3.78 GPa. With increasing pressure, (1) the volumes of the TO4 tetrahedra do not vary, (2) the volume of the NaO7 polyhedron varies linearly with the volume of the unit cell and (3) Si-O-Si angles increase or remain constant, but only Al-O-Si angles decrease, which is consistent with the smaller force constant of the Al-O-Si vs. Si-O-Si angle. It is concluded that compression is accomplished through the bending of Al-O-Si angles, which squeezes together the chains of four-membered rings that run parallel to [001] and that are separated by zigzag channels containing Na atoms. -from Authors
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1042-1052 |
| Number of pages | 11 |
| Journal | American Mineralogist |
| Volume | 79 |
| Issue number | 11-12 |
| State | Published - 1994 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Geochemistry and Petrology
- Geophysics
Cite this
The high-pressure crystal chemistry of low albite and the origin of the pressure dependency of Al-Si ordering. / Downs, Robert T; Hazen, R. M.; Finger, L. W.
In: American Mineralogist, Vol. 79, No. 11-12, 1994, p. 1042-1052.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The high-pressure crystal chemistry of low albite and the origin of the pressure dependency of Al-Si ordering
AU - Downs, Robert T
AU - Hazen, R. M.
AU - Finger, L. W.
PY - 1994
Y1 - 1994
N2 - Structural and volume compressibility data for low albite were obtained by single-crystal X-ray diffraction methods at pressures up to ~4 GPa. The bulk modulus was determined to be 54(1) GPa, with a pressure derivative of 6(1). Intensity data were collected, and structures were refined at 0.00, 0.44, 1.22, 2.68, and 3.78 GPa. With increasing pressure, (1) the volumes of the TO4 tetrahedra do not vary, (2) the volume of the NaO7 polyhedron varies linearly with the volume of the unit cell and (3) Si-O-Si angles increase or remain constant, but only Al-O-Si angles decrease, which is consistent with the smaller force constant of the Al-O-Si vs. Si-O-Si angle. It is concluded that compression is accomplished through the bending of Al-O-Si angles, which squeezes together the chains of four-membered rings that run parallel to [001] and that are separated by zigzag channels containing Na atoms. -from Authors
AB - Structural and volume compressibility data for low albite were obtained by single-crystal X-ray diffraction methods at pressures up to ~4 GPa. The bulk modulus was determined to be 54(1) GPa, with a pressure derivative of 6(1). Intensity data were collected, and structures were refined at 0.00, 0.44, 1.22, 2.68, and 3.78 GPa. With increasing pressure, (1) the volumes of the TO4 tetrahedra do not vary, (2) the volume of the NaO7 polyhedron varies linearly with the volume of the unit cell and (3) Si-O-Si angles increase or remain constant, but only Al-O-Si angles decrease, which is consistent with the smaller force constant of the Al-O-Si vs. Si-O-Si angle. It is concluded that compression is accomplished through the bending of Al-O-Si angles, which squeezes together the chains of four-membered rings that run parallel to [001] and that are separated by zigzag channels containing Na atoms. -from Authors
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UR - http://www.scopus.com/inward/citedby.url?scp=0028669518&partnerID=8YFLogxK
M3 - Article
VL - 79
SP - 1042
EP - 1052
JO - American Mineralogist
JF - American Mineralogist
SN - 0003-004X
IS - 11-12
ER -