How fungal threads extract minerals from stone
A fungus does not need to eat a piece of rock to obtain what is locked inside it. Its fine filaments, called hyphae, grow into tiny cracks and press against mineral grains. The fungus releases acids and other compounds that weaken the mineral surface. Some compounds also bind to released elements, helping keep them available for uptake rather than letting them immediately attach to something else.
This is a slow form of chemical weathering: minerals break down at the surface, releasing nutrients such as phosphorus, potassium, or iron. The fungus absorbs dissolved nutrients through its hyphae. The solid mineral itself stays behind; what moves into the fungus is a small amount of material released from it.
Why plants can benefit
Many fungi form mycorrhizal partnerships with plant roots. The fungal filaments can explore narrow pores and patches of soil that roots cannot reach easily, including surfaces where minerals are weathering. Nutrients taken up by the fungus can become available to its plant partner; in return, the plant supplies sugars made through photosynthesis.
The arrangement does not make rock an unlimited food source, and the rate of mineral release is gradual. But it gives fungi—and, through some partnerships, plants—a way to tap nutrients in places where ordinary roots find little to absorb. A bare-looking mineral surface can therefore be part of a living nutrient supply, worked grain by grain by threads too fine to see.
