This is a very interesting question, since minerals can be stored in a lot of places. First, it’s important to understand what the exact definition of a mineral is. For something to be considered to be a mineral, it must:

What I mean by a well-defined chemical composition is that a mineral is always composed of the same proportions of different elements. For example, the mineral quartz is always composed of silicon and oxygen, with there being two oxygen atoms to every silicon atom (SiO₂).

When I say that a mineral has a specific crystal structure, what I mean is that the way that the atoms within a mineral are arranged is always the same, no matter where that mineral came from. For example, table salt, also known as halite, is a mineral composed of one sodium atom (Na) to every chlorine atom (Cl). In halite, these two atoms are always arranged such that they make crystalline cubes at the atomic level. This is why if you look at salt really closely, it’s made of a bunch of little cubes!

Now, there are lots of different kinds of minerals and they can be found all over earth. Minerals are the building blocks of all rocks, so every single rock that you find is essentially storing different minerals. In addition to being found in rocks, minerals can be created and stored inside the bodies of living things, including humans through a process called biomineralization. In fact, seashells and bones are two good examples of where minerals are stored in living things! The bones and teeth in your body contain versions of the mineral hydroxyapatite..

Finally, since water ice in the polar ice caps is naturally occurring, has a well-defined chemical composition (H₂O), and has a specific crystal structure, it can also be considered a mineral. Therefore, you could even say that minerals (ice) are stored in glaciers, polar ice caps, and anywhere with snow!