In the photon double-slit experiment, it has been proven that one singular particle can pass through two holes at the same time. However, when you set up detectors it's as if the particles have become aware of the experiment and only go through one hole.
With this same concept, theories have been constructed implying a dual co-existence. "Matter cannot be destroyed, nor created." - Albert Einstein
-However, it can change.
If two antiparticles collide (electron + positron for example), their mass is fully converted into energy (photons). Does that destroy matter? If you regard photons as matter than no, it doesn't. But if you don't regard