Gypsum

Gypsum is a kind of rock that is made up of a chemical called calcium sulfate. Calcium sulfate is a white powder that is sometimes used to make things like plaster of Paris or drywall. When you mix gypsum with water, it turns into a paste that can be molded into different shapes. It's kind of like playing with wet sand at the beach!

One really cool thing about gypsum is that it can absorb water. This means that if you leave a piece of gypsum in water for a little while, it will soak up some of the water and get bigger. This is why gypsum can be used to make certain types of soil that are good for growing plants.

Gypsum is also found in nature, usually in large, white crystals. People have been mining this type of gypsum for thousands of years and using it for various purposes. In fact, the ancient Egyptians used gypsum to make plaster for their buildings and sculptures.

So, in summary, gypsum is a type of rock that can be molded into different shapes when mixed with water. It can also absorb water and is used for things like making drywall and soil for growing plants.