That one guy named Einstein proved that particles are waves and waves are particles and therefore by the 1st law of thermodynamics matter/energy can be created nor destroyed.....unless of course you're GOD!!!
If you would like more of an esoteric answer, then one can only know of matter within one's consciousness. Or another way of seeing it as matter cannot exist within ones consciousness with out the energy of spirit. Thus, spirit + matter = consciousness...but we do not "create" matter! Get it ??!?!?
Can it be destoyed...hmmmmm, I guess you will have to wait till your next time around on the physical plane to answer that one.