There are two blocks that, on their own, are largely useless in Minecraft: sand and gravel. These are arguably the most annoying ones, especially when mining. Apart from that, their tendency to fall on top of things can be dangerous.
They both can be used for other things, though. For example, sand is smelted into glass and gravel can produce flint, which is used for flint and steel. Together, though (with the help of some other things) they can make a useful item: concrete powder.
Here's how to acquire it in Minecraft.
Getting concrete powder in Minecraft
Concrete is a tremendous building block in Minecraft and can be colored to make exactly what a Minecraft player wants. It's not very common, though, at least in Survival mode.
Making concrete is fairly simple as it is concrete powder that has water flowing over it. It can be from a body of water or just a bucket.
Concrete powder, though, is a bit harder to come by. It's not a common item, so the crafting recipe is probably unknown to most players. Whatever color the concrete powder needs to be should be added via dye.
For example, a black dye (from ink sacs that are dropped by squids) combined with four gravel and four sand blocks will create concrete powder. Changing the dye will change the color. Dye is necessary even if players are just trying to make generic concrete.
Once crafted, simply use the water and it will turn into concrete and players can build with it. Note that breaking it without a pickaxe will result in a lost block. Finally, there is a use for the three stacks of gravel that players return with after mining and all the sand that is incredibly easy to find.
It is brighter and more pronounced in color than terracotta and isn't flammable like wool, so it is the best way of decorating and building with color. It is also used for note blocks.