system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does the cremation process actually work?
gpt
Basically a body is put in a cheap easily burned container, a cardboard or thin wood casket, it's then burned at an extremely high temperatures in a gas furnace, called a 'retort' until all moisture has been removed, all tissues have been reduced to just some carbon ash and trace minerals, and the bones are reduced to extremely brittle chunks of dry calcium. It's the bones that form the majority of the 'ashes'. After burning, the cremains are tumbled with steel balls or processed through a bladed grinder (known as a Cremulator) to produce a powder that resembles fine gravel. 

So in realty, the majority of cremation 'ashes' are actually just incinerated powdered bones.