Control hidroquímico del aluminio tetraédrico en cuarzo, haloisita, ilita y otros silicatos de baja temperatura

• Autores: E. Merino
• Localización: Boletín de la Sociedad Española de Mineralogía, ISSN 0210-6558, Vol. 11, Nº 2, 1988, págs. 18-21
• Idioma: español
• Enlaces
  • Texto Completo Ejemplar
• Resumen

  • Increasing pH of aluminum-bearing aqueous solutions causes the aluminum to pass from octahedral to tetrahedral coordination over a narrow pH interval: 5.it to 5.7 at 25°C and 3-8 to A.2 at 100°C. Silicates that grow from solutions having pH > 5.7 should incorporate significant A1 substituting for Si, but should not do so for pH < 5.4. This prediction applies to quartz, opal-CT, and many phyllosilicates; it links the pH to halloysite's typical Al(tetrahedral) content and tubular morphology; and it is consistent with water-mineral pairs from low-temperature occurrences.