Rhassoul or ghassoul (Moroccan Arabic: الغاسول, translit. l-ġasul) is a cosmetic made of natural mineral clay mined from the Atlas Mountains of Morocco. It is combined with water to clean the body and has been used by North African women for centuries to care for their skin and hair. Rhassoul contains silica, iron, magnesium, potassium, sodium, lithium, and trace elements.
The use of rhassoul dates back to the eighth century. Today, rhassoul is mainly used in Traditional Moroccan Hammams and in Turkish baths. Along with a glove, or "kessa", Rhassoul is used as a facial mask and poultice to the body. It is similar to a western style mud wrap. It is intended to soften the skin, reduce sebum secretion, regenerate the skin by removing dead cells, and rebalance the skin by tightening the pores. 
Rhassoul clay is also used for hair washing. It is a suggested substitution for shampoo. Moreover rhassoul is useful for dandruff prevention and head skin nurturance. It is recommended to be used with natural oils or use oils after washing your head.[better source needed]
"Rhassoul does not replace shampoo, but can be used on greasy hair twice a week, and once a week on dry hair. It will not affect the color of dyed hair."
- The Complete Idiot's Guide to Making Natural Beauty Products by Sally W. Trew, Zonella B. Gould
- Handbook of Medical Tourism Development by María Todd, p. 202 
- Ask Question Online - Rhassoul clay for hair washing
- "Rhassoul hair mask | Moroccan Hammam Natural Beauty Care". Moroccan Hammam. Retrieved 2016-11-15.