Many technical terms used in the Earth sciences are derived from foreign languages such as Greek and Latin and are not easily comprehensible to beginners.  However, knowledge of the root words from which these technical terms are formed not only makes learning of the concepts represented easier, but also helps to quickly understand new terms that may be encountered.  This paper considers about 1,600 technical terms that derive from about 300 root words.  Learning the Earth sciences vocabulary thus reduces to learning a much smaller assortment of root words.  Dominant contributors to the vocabulary are the Greek root words isos, lithos, gennaine, ge, klinein, morphe, meta, orthos, para, klasis, chronos, pseudes, strophe, tropos as well as some Latin roots such as stratum, fluvius, etc.  As language skills usually develop quite early and new vocabulary is acquired more slowly with age, a genetic treatment of the Earth science vocabulary early on is expected to help the student develop a keen aptitude and an enduring interest in the subject.