Kaolin wani ma'adinai ne da ba na ƙarfe ba, wani nau'in dutse ne na yumbu da yumbu wanda ma'adanai na yumbu na kaolinite suka mamaye. Saboda fari ne kuma mai laushi, ana kuma kiransa da ƙasa mai farin gajimare. An sanya masa suna ne bayan ƙauyen Gaoling, garin Jingde, Lardin Jiangxi.

Tsarkakken kaolin ɗinsa fari ne, mai laushi kuma mai laushi kamar yumbu, kuma yana da kyawawan halaye na zahiri da sinadarai kamar su filastik da juriya ga wuta. Abubuwan da ke cikin ma'adinansa galibi sun ƙunshi kaolinite, halloysite, hydromica, illite, montmorillonite, quartz, feldspar da sauran ma'adanai. Kaolin yana da amfani iri-iri, galibi ana amfani da shi wajen yin takarda, yumbu da kayan da ba sa jure wa iska, sai kuma shafa fenti, cika roba, glazes na enamel da kayan siminti na farin siminti, da kuma ƙaramin adadin da ake amfani da shi a cikin robobi, fenti, launuka, ƙafafun niƙa, fensir, kayan kwalliya na yau da kullun, sabulu, maganin kashe kwari, magani, yadi, man fetur, sinadarai, kayan gini, tsaron ƙasa da sauran sassan masana'antu.
Hasken Farin da aka Ninke
Farin fata yana ɗaya daga cikin manyan ma'aunin aikin fasaha na kaolin, kuma kaolin mai tsarki sosai fari ne. Farin fata na kaolin an raba shi zuwa fari na halitta da fari bayan calcination. Ga kayan yumbu, farin fata bayan calcination ya fi mahimmanci, kuma mafi girman farin fata, ingancinsa ya fi kyau. Fasahar yumbu ta ƙayyade cewa bushewa a 105°C shine ma'aunin ma'aunin farin fata na halitta, kuma calcining a 1300°C shine ma'aunin ma'aunin ma'aunin farin fata. Ana iya auna farin fata da mitar farin fata. Mita farin fata na'ura ce da ke auna hasken haske tare da tsawon tsayi na 3800-7000Å (watau Angstrom, 1 Angstrom = 0.1 nm). A cikin ma'aunin fari, kwatanta hasken samfurin da za a gwada da samfurin da aka saba (kamar BaSO4, MgO, da sauransu), wato, ƙimar farin (misali, farin 90 yana nufin 90% na hasken samfurin da aka saba).

Haske wani tsari ne mai kama da fari, wanda yayi daidai da fari a ƙarƙashin hasken hasken raƙuman ruwa na 4570Å (Angstrom).

Launin kaolin yana da alaƙa da ƙarfe oxides ko kwayoyin halitta da ke cikinsa. Gabaɗaya, yana ɗauke da Fe2O3, wanda ja ne mai launin ruwan hoda da launin ruwan kasa mai launin rawaya; yana ɗauke da Fe2+, wanda launin shuɗi ne mai launin kore; yana ɗauke da MnO2, wanda launin ruwan kasa ne mai launin ruwan kasa; yana ɗauke da kwayoyin halitta, wanda launin rawaya ne mai launin toka, shuɗi, da baƙi. Kasancewar waɗannan ƙazanta yana rage farin kaolin na halitta, kuma ma'adanai na ƙarfe da titanium suma suna shafar farin calcine, suna haifar da tabo ko tabo a cikin faranti.