Sentence:  To encourage exploration for domestic sources of <WSD>minerals</WSD> , the Office of Minerals Exploration ( OME ) of the U.S. Department of the Interior offers financial assistance to firms and individuals who desire to explore their properties or claims for 1 or more of the 32 mineral commodities listed in the OME regulations . 
Meaning of the word marked with <WSD> tags:  solid homogeneous inorganic substances occurring in nature having a definite chemical composition