Well, it ultimately depends on what kind of minerals, right?! Finding precious metal deposits, (gold, silver, etc.) under your house would be great, but so far our countless thousands of inspections have only found a pattern of mineral deposits like the one in the picture above...

This type of deposit, known technically as "efflorescence", is a crystalline deposit on surfaces of masonry, stucco or concrete. It is whitish in appearance, and has a very soft character to the touch, but can be indicative of issues needing resolution. The formation of these salt deposits are not mysteries. They are, for the most part, water-soluble salts that come primarily from adjacent moisture sources and which detract from an other­wise structurally sound and serviceable structure. First of all, there must be water present to dissolve and trans­port the salts. For water to carry or move the salts to the surface there must be channels through which to move and migrate. The more dense the material, whether it be brick, stone, stucco or concrete, the more difficult for the water to transport salts to the surface. Conversely, the more porous the material, the greater the ease with which salts are transported and deposited. Salt-bearing water, on reaching the surface of a structure, evaporates to deposit the salt such as you see happening to this defensive concrete support pier under a beautiful Spanish-era home in Hancock Park.

I could go on, but the point here is to remind one and all that despite the wonderful weather we are currently experiencing, it is of such paramount importance to be sure that the area surrounding your home is protected from any sources of water that may be causing efflorescence under it.