Methane clathrates, also known as methane hydrate is when methane becomes trapped in a water crystal structure. To be clear, this isn't something that happens in places the average person would come across, but it's found in various places on the ocean's floor.
It's currently being studied as an alternative energy source and scientists are trying to find clean ways to produce it that can be put to use in everyday life. This sample is likely man-made.
