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Chemical substance record

Kaolin

1332-58-7Al2O7Si2.2H2O258.159 g/mol
MineralChEBI source record

An aluminosilicate soft white mineral named after the hill in China (Kao-ling) from which it was mined for centuries. In its natural state kaolin is a white, soft powder consisting principally of the mineral kaolinite, and varying amounts of other minerals such as muscovite, quartz, feldspar, and anatase. It is used in the manufacture of china and porcelain and also widely used in the production of paper, rubber, paint, drying agents, and many other products. — ChEBI

Safety references

Safety documents & references

1 indexed references
US · NIOSH

Occupational chemical safety guide

Kaolin

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Identity & molecular properties

Source-linked values
CAS number1332-58-7ChEBI ↗
Molecular formulaAl2O7Si2.2H2OChEBI ↗
Molar mass258.159 g/molChEBI ↗
Monoisotopic mass257.90246 DaChEBI ↗
Formal charge0ChEBI ↗
ChEBI identifierCHEBI:140503ChEBI ↗

Cross-source molecular data

PubChem
Molar mass258.16 g/molPubChem ↗
Exact mass257.902462 DaPubChem ↗

PubChem computed values are shown separately from the ChEBI record. An exact InChIKey match was used to connect the records. Molecular descriptors do not describe a supplied product’s purity, particle size or performance.

Names & structural identifiers

Copy any identifier
kaolin
oxo-oxoalumanyloxy-[oxo(oxoalumanyloxy)silyl]oxysilane;dihydrate
NLYAJNPCOHFWQQ-UHFFFAOYSA-N
O.O.[O]=[Al][O][Si](=O)O[Si](=O)[O][Al]=[O]
InChI=1S/2Al.O5Si2.2H2O.2O/c;;1-6(2)5-7(3)4;;;;/h;;;2*1H2;;/q2*+1;-2;;;;

Classification & relationships

ChEBI ontology

Roles recorded in ChEBI

antidiarrhoeal drugexcipient

Database role annotations describe reported biological or chemical roles; they are not product approvals or recommendations for use.

Mass ↔ amount of substance

Calculated from sourced mass
Equivalent amount
0.00387358 mol

Uses 258.159 g/mol from ChEBI. Assumes the substance described by this record; no purity or concentration correction is applied.

Elemental composition

Theoretical mass fractions
Si
Silicon · 22 atoms
77.06%
O
Oxygen · 8 atoms
15.96%
Al
Aluminum · 2 atoms
6.73%
H
Hydrogen · 2 atoms
0.25%

Calculated theoretical mass fractions from the reported formula and PubChem periodic-table atomic masses. These are not assay or purity results.

Research & patent references

Selected source associations
Genotoxicity of micro- and nano-particles of kaolin in human primary dermal keratinocytes and fibroblasts. ↗Genes and environment : the official journal of the Japanese Environmental Mutagen Society · 2020 · PMID 32322315

Sources & record history

Checked 27 Sep 2026
EMBL-EBI ChEBI · CHEBI:140503

Release 255, 9 September 2026. ChEBI three-star (manually annotated) source entry. View original record ↗ · CC BY 4.0

NCBI PubChem · CID 56841936 · retrieved 2026-09-27

PubCAS formats source data, connects references and computes explicitly labelled conversions. CAS cross-references are supplied by ChEBI; they do not constitute CAS verification or endorsement.