Here's why:

* Naturally Occurring: The vast majority of minerals are indeed found naturally in the Earth's crust, mantle, and even core. These minerals form through geological processes like crystallization from magma, precipitation from water, or the transformation of other minerals.

* The Caveat: Synthetic Minerals: While most minerals are natural, scientists and engineers have created synthetic minerals in laboratories. These man-made minerals have the same chemical composition and crystal structure as their natural counterparts but are produced under controlled conditions. Examples include synthetic diamonds, rubies, and sapphires.

Therefore, while most minerals occur naturally, it's not entirely accurate to say *all* minerals do.