the branch of chemistry dealing with petroleum or its products.
the chemistry of rocks.
Origin of petrochemistry
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
the chemistry of petroleum and its derivatives
the branch of chemistry concerned with the chemical composition of rocks
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012