C

Clay

Al₂Si₂O₅(OH)₄
Quick Reference
Formula / NotationAl₂Si₂O₅(OH)₄
Also Known AsClay minerals, phyllosilicates, aluminosilicate clays, layer silicates

What is Clay?

Clay is a naturally occurring fine-grained mineral material composed mainly of phyllosilicate minerals with layered structures. Clays are important in chemistry as ion-exchange materials, catalyst supports, and as components of soils. They carry negative surface charges that attract and hold cations, contributing to soil fertility. Kaolin, montmorillonite, and illite are common clay minerals.

Formula & Notation

Al₂Si₂O₅(OH)₄

Other Names / Synonyms: Clay minerals, phyllosilicates, aluminosilicate clays, layer silicates

Properties & Characteristics

Clay minerals are hydrated aluminosilicate layer minerals with sheet-like structures. They form by weathering of feldspars and other silicates. Common types include kaolinite, montmorillonite, illite, and smectite. Clays are plastic when wet (colloidal particle size), rigid when dry, and vitrify when fired. They carry negative surface charges that attract cations and water, giving them high cation exchange capacity (CEC).

Uses & Applications

Clays are used in ceramics, pottery, bricks, paper coating, paints, drilling mud (bentonite), cat litter, pharmaceuticals (kaolin as antidiarrheal), and as catalyst supports (acid-treated montmorillonite). Pillar clays are used as shape-selective catalysts in cracking.

Safety Information

Fine clay dust is a respiratory irritant and can cause silicosis with prolonged exposure to crystalline silica-containing clays. Wet clay poses a slip hazard. Certain smectite clays swell significantly when wet, which can cause structural hazards in construction.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Clay
Formula Al₂Si₂O₅(OH)₄
Synonyms Clay minerals, phyllosilicates, aluminosilicate clays, layer silicates

Frequently Asked Questions

Clay is a naturally occurring fine-grained mineral material composed mainly of phyllosilicate minerals with layered structures. Clays are important in chemistry as ion-exchange materials, catalyst supports, and as components of soils. They carry negative surface charges that attract and hold cations, contributing to soil fertility. Kaolin, montmorillonite, and illite are common clay minerals.

More "C" Terms

View all "C" terms →
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z