Possible Use of CCN in Mineralogy
Although not a very developed practice in mineralogy, some chemical reactions involving silicate and oxide in the melt or in hydrothermal systems, and silicate weathering processes could also be successfully described by applying the cement chemist notation to silicate mineralogy.
An example could be the formal comparison of belite hydration and forsterite serpentinisation dealing both with the hydration of two structurally similar earth -alkaline silicates, Ca2SiO4 and Mg2SiO4, respectively.
Calcium system: belite hydration:
- Belite + water → C-S-H phase + portlandite
- 2 Ca2SiO4 + 4 H2O → 3 CaO · 2 SiO2 · 3 H2O + Ca(OH)2
- 2 C2S + 4 H → C3S2H3 + CH
Magnesium system: forsterite serpentinisation:
- Forsterite + water → serpentine + brucite
- 2 Mg2SiO4 + 3 H2O → Mg3Si2O5(OH)4 + Mg(OH)2
- 2 M2S + 3 H → M3S2H2 + MH
The ratio Ca/Si (C/S) and Mg/Si (M/S) decrease from 2 for the di-calcium and di-magnesium silicate reagents to 1.5 for the hydrated silicate products of the hydration reaction. In other term, the C-S-H or the serpentine are less rich in Ca and Mg respectively. This is why the reaction leads to the elimination of the excess of portlandite (Ca(OH)2) and brucite (Mg(OH)2), respectively, out of the silicate system, giving rise to the crystallization of both hydroxides as separate phases.
The rapid reaction of belite hydration in the setting of cement is formally "chemically analogue" to the slow natural hydration of forsterite (the magnesium end-member of olivine) leading to the formation of serpentine and brucite in nature. However, the kinetic of hydration of poorly crystallized artificial belite is much swifter than the slow conversion/weathering of well crystallized Mg-olivine under natural conditions.
This comparison suggests that mineralogists could probably also benefit from the concise formalism of the cement chemist notation in their works.
Read more about this topic: Cement Chemist Notation