>>106573433
It's actually a really bad idea to put rocks in a microwave. I learned at a pretty young age that rocks are very porous and can contain a lot more water than you might think. Because of this if you put them near heat the water inside will expand more quickly than can be released via steam, causing pressure to build inside which can cause the rocks to crack open violently, sometimes rocketing small bits that can cause serious injury. This is why you never use rocks from a nearby water source as a ring for a firepit and have to be careful of any firepit rocks after a heavy rain.