Definition: Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.
Input: Sentence1: Also pyrite within the altered wall rock is oxidized to limonite, geothite and hematite. 
Sentence2: chemical weathering causes pyrite to change to limonite, geothite and hematite.

pyrite