Illite 2 : A clay type of varying form and composition. Rarely water sensitive. May occur in unusual cases as a fiberous deposit that can act as a particle trap
George E. King Engineering, 5000 Oilfield Terms: A Glossary of Petroleum Engineering Terms, Abbreviations and Acronyms, US 2010. http://gekengineering.com/Downloads/Free_Downloads /Glossary_of_Petroleum_Engineering_Terms_25_August _2010.pdf, (Oil - Amer) {593}