Calinou's Law

Calinou's Law is a supposition about the density of ores in Minetest. It states, approximately:

The more ores that are registered, the more likely you will be to find nothing BUT ores by the time you dig down to -31 km.

In theory, one could reach a state in a game where there are indeed nothing but minerals and no plain stone at some depth by adding enough ore-bearing mods, however this particular idea refers more to the issue some people have of going on a mining expedition and coming back so loaded down with ores that one has no room in their inventory for anything else, such as cobblestone. Calinou's Law is this phenomenon taken to its logical extreme.

Compare "rainbow caves" phenomenon, wherein there are so many minerals in a given area that cave walls take on a multicolor or "rainbow" appearance.