Bone ash is a special white powder that is made from animal bones. When animals die, their bones are left behind. People used to throw away these bones, but then someone discovered that they could be turned into a special type of powder called bone ash.
To make bone ash, people take the leftover bones and heat them up in a special oven called a furnace. This oven gets really hot, much hotter than the one in Mommy's kitchen! The heat makes the bones turn into a powdery substance which people then grind up into a fine powder.
What's so special about bone ash, you may ask? Well, it turns out that this powder is useful in many different ways. For example, people use it to make ceramics, pottery, and even some types of glass. Because it is white, bone ash can help make these things look extra pretty and shiny.
Some people also use bone ash as a fertilizer for their gardens. It provides important nutrients to help plants grow big and strong. And, in ancient times, bone ash was even used for medicine because people believed it could cure all sorts of illnesses!
So, the next time you see a pile of old animal bones, remember that they could be turned into something very useful and important: bone ash.