Helium- in addition to making balloons fun and floaty and giving people high squeaky voices, helium is used as a coolant for particle colliders and satellites AND is a component of superconducting magnets in MRI machines.
Helium is usually obtained as a byproduct of radioactive decay of uranium OR from natural gas. Once helium is released into the atmosphere, it is nearly impossible to reclaim.
Peat- is a brown, boggy, soil-like material made of decaying plants and animals. It is found in bogs and it takes thousands to ten thousands of years to form.
In certain parts of the world, peat is used as a major fuel source- even to the point of being used by power stations in Ireland. It is also used in water filtration processes and in agriculture as an additive to soil to help retain nutrients.
Bismuth is a heavy metal that is commonly used in cosmetics, pigments, and some pharmaceuticals. While bismuth can be reused if it is recycled, many of its current uses lead to a scattering of molecules that makes it impossible to reclaim the metal.
Uranium is the main fuel used by nuclear power plants. While the metal is common, only one type or uranium- U235- can be used as fuel. Once it is mined, it must also be extracted and processed. Once the uranium ore is spent, it cannot be reused and instead must be stored securely.
Plastic- so many things in our daily lives are made from plastic. Beads, blocks, furniture, toys, styrofoam, flatware, phone cases, markers. The list goes on and on.
Unfortunately, all plastics are made mostly from oil and natural gas. Crude oil takes millions of years to form. Furthermore, plastics do not degrade. Once plastic is made into something, we are stuck with that item as permanent garbage.