What type of clay mineral is Kaolinite?

✅Explanation:
Kaolinite is a 1:1 clay mineral, meaning its structure consists of one layer of octahedral sheets linked to one layer of tetrahedral sheets.

📌Other Options:
-2:1:1: This type, like mica, has two tetrahedral sheets sandwiching one octahedral sheet.
-2:1 expanding: This type, like smectite, also has a 2:1 structure but expands upon hydration due to weak bonding between layers.
-2:1 non-expanding: This type, like illite, has a 2:1 structure with stronger bonding between layers, preventing expansion.

🔑IMP Key Points:
-
-Kaolinite: Hydrogen bonds
-Two-layer unit formed by stacking a gibbsite sheet on a silica sheet.
-Stable and does not expand under saturation.
-Illite: Potassium ions
-Consists of basic montmorillonite units bonded by potassium ions.
-Stable and shows minimal swelling or shrinking.
-Montmorillonite: van der Waals forces
-Weak bonding allows water to enter easily.
-Can absorb large quantities of water, leading to significant swelling.

•  With reference to grain size:
-Kaolinite > Illite > Montmorillonite

•  With reference to swelling and shrinkage behavior:
-Montmorillonite > Illite > Kaolinite

•  With reference to Plasticity Index:
-Montmorillonite > Illite > Kaolinite

🛑 Related Terminology:
-Tetrahedral sheet: Composed of silicon atoms surrounded by four oxygen atoms, forming a pyramid shape.
-Octahedral sheet: Composed of aluminium or magnesium atoms surrounded by six oxygen or hydroxyl groups, forming an octahedron shape.