There is actually a lot of acreage in Texas that has some quantities of Lithium. The USGS just actually released a Lithium map showing concentrations of Lithium (measured in milligrams per kilogram) across the continental United States. Hopkins (as can be seen in the heatmap below) does show in one of these good areas. Now, whether this indicates the presence of possible petrolithium or actual lithium rock I am unaware. Pioneer is experimenting with lithium extraction methods from frack wastewater.
Pioneer (PXD) Is Trying to Mine Lithium From Dirty Permian Fracking Water - Bloomberg . Here is an article from University of Texas that goes into a bit of detail (though this may differ from the methods Pioneer is using. New Way to Pull Lithium from Water Could Increase Supply, Efficiency - UT News (utexas.edu)
It would be great if anyone with experience could weigh in on the potential! Especially for mineral owners in the Permian Basin. Anyway, here is the map!
Note: This is for Soil C Horizon, which seems to be the deepest level. I put a thumbtack where Hopkins County is.