I live in the state of Illinois. Can land and minerals that have a land patent on them be sold? The record books in our recorder’s office show there are well over 3,000 illegal land mineral deeds.

Yes.

A land patent is just a grant from the sovereign (either the state or the Federal government) to someone. A grant can have reversionary rights — for example, that you give the land to Mr. X for 20 years, but then it reverts back to you — but more typically land grants are without restriction.

Once that someone owns the land, the owner is free to sell to anyone they want to. Mining or other mineral rights work much the same way — though they can, and often are, transferred separately from the land itself.

If a deed is illegal, that’s one thing, but the mere fact of a historical patent doesn’t necessarily restrict transfer.