Kaolin

**Definition:** The most common mineral of a group of hydrated aluminum silicates, approximately H2Al2Si2O8-H2O. It is prepared for pharmaceutical and medicinal purposes by levigating with water to remove sand, etc. (From Merck Index, 11th ed) The name is derived from Kao-ling (Chinese: high ridge), the original site. (From Grant & Hackh's Chemical Dictionary, 5th ed)

**Tree numbers:** - D01.056.050.075.350 - D01.578.725.025.350 - D01.650.550.050.075.350 - D01.837.725.700.760.050.400