majoritic garnet
Mg0.31Fe1.4Ca0.82K0.06Al0.67Si3.9O12 (synthesized from natural tholeiitic basalt)
third-order Birch-Murnaghan · Original · 1996
Why this differs from similar rows?
Alternative equally-acceptable fit with K0 constrained to 180 GPa (matching ambient elasticity of related garnets), giving K'=7; sibling row instead floats K0 to 226.2 GPa.
V₀
—
Unknown basis
K₀
180
GPa
Isothermal
K′
7
dimensionless
Volume (V₀)
| Value | Unit | Basis | Z |
|---|---|---|---|
| — | — | Unknown basis | — |
Reported value and unit are preserved as extracted. Z (formula units per cell) is not stored yet, so molar ↔ ų/f.u. conversion is not applied automatically.
Composition
| Oxide | Molar |
|---|---|
| MgO | 0.31 |
| FeO | 1.4 |
| CaO | 0.82 |
| K2O | 0.03 |
| Al2O3 | 0.335 |
| SiO2 | 3.9 |
Formula: Mg0.31Fe1.4Ca0.82K0.06Al0.67Si3.9O12
Conditions & method
- Tref
- 300 K
- Pref
- —
- Structure
- other / unspecified
- Method
- experiment (XRD / DAC / multianvil compression)static compression, x-ray diffraction in diamond-anvil cell (300 K)
- Sample
- basaltic garnet synthesized from natural tholeiite at ~20.8 GPa, laser-heated diamond cell (alternative fit)
Source
- Paper
- The stability and equation of state of majoritic garnet synthesized from natura…
- Authors
- J. W. Faust; Elise Knittle
- DOI
- 10.1029/96gl03027
- Year
- 1996
- Journal
- Geophysical Research Letters
- Origin
- Original (measured or fitted in the source paper)
Evidence from the paper
An equally acceptable fit to the data is obtained if K0T is constrained to be 180 GPa and dK0T/dP is 7 (±1). ... we also constrain K0T to be 180 GPa, a value consistent with ambient pressure elasticity results for synthetic pyrope-almandine garnets and majoritic garnets. For this lower value of the bulk modulus, an acceptable fit to our static compression data is obtained when K0' is 7 (±1).
Additional notes
a0
11.491(±0.011) Å (zero pressure lattice parameter)
rho0
3.83 (±0.02) g/cm^3