Properties of Kaolinite

Kaolinite is a clay mineral and a member of the kaolin group, which also includes dickite, nacrite, and halloysite. It is one of the most common clay minerals and is the principal constituent of kaolin, a type of fine-grained, soft clay.

Image of kaolinite mineral
Credit: Marie-Lan Taÿ Pamart, CC BY 4.0, via Wikimedia Commons

The following table provides a comprehensive list of kaolinite properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).

Note: click on the icon to switch between Metric and Imperial units.

Table of Kaolinite Properties
Physical Properties
Metric
Chemical FormulaAl2Si2O5(OH)4
Molar Mass516.32 g/mol
Crystal SystemTriclinic
Mohs Hardness2 - 2.5
Density2600 kg/m3
ColorWhite, brownish white, grayish white, yellowish white, or grayish green
DiaphaneityTransparent to translucent
LusterDull
Cleavage(001) perfect
FractureFlexible
StreakWhite

Note: unless stated otherwise, all values are taken at room temperature (approximately 20°C or 68°F) and 1 atm pressure. (1 atm = 101,325 Pa)

Related Pages
References: 1) Cardarelli, François. Materials Handbook: A Concise Desktop Reference. Switzerland: Springer International Publishing, 2018. 2) CRC Handbook of Chemistry and Physics, 97th Edition. United Kingdom: CRC Press, 2016-2017.