Kaolin & clays
Kaolin, bentonite and other clays: fine-grained minerals that whiten paper and paint, shape ceramics, bind drilling mud and fill cat litter.
Industrial minerals · No. 66
- Not on a critical list
- HHI 1,009 · unconcentrated
Nearly half of US bentonite ends up as pet litter, while bright kaolin whitens paper and paint around the world.
Chart: Illustration: Kaolin & clays
Where it comes from
Chart: Map of where it comes from
Clays form where rocks weather or alter. Kaolin comes from deeply weathered granites and sediments, as in Georgia and Brazil; bentonite from altered volcanic ash. Kaolin output was about 49 Mt in 2024.
Three things to know
- US common clay sells for about $21 per tonne and kaolin for about $170, so ordinary clay barely travels.
- Bentonite forms from altered volcanic ash and swells in water; 22% of US bentonite went into drilling mud in 2025.
- Lithium had never been produced commercially from clay before projects such as Thacker Pass in Nevada.
The journey
- 1 Parent rockWeathered granite, sediment or volcanic ash
- 2 Open pitClay dug from shallow pits
- 3 RefiningSlurried, degritted, magnetically cleaned, bleached
- 4 FinishingDelaminated or calcined; bentonite dried, activated
- 5 End usesPaper, paint, ceramics, drilling mud, absorbents