Figure 2
From: What is the mechanism of formation of hydroxyaluminosilicates?

Binding of silicic acid molecule to (a) an aluminium hydroxide dimer to form HASA and (b) a HASA unit to form HASB.
From: What is the mechanism of formation of hydroxyaluminosilicates?
Binding of silicic acid molecule to (a) an aluminium hydroxide dimer to form HASA and (b) a HASA unit to form HASB.