Lewis and Clark didn't focus on identifying specific minerals during their expedition. Their primary goal was exploration and mapping, and they documented the geology and geography of the western United States. While they observed rocks and formations, their observations weren't detailed enough for us to know exactly what minerals they encountered.

However, based on the regions they traveled through, we can infer that they likely saw:

* Rocks and minerals typical of the Rocky Mountains: These include granite, gneiss, schist, quartz, and feldspar.

* Minerals associated with volcanic activity: The expedition crossed through volcanic regions in present-day Idaho and Montana. They might have observed minerals like obsidian, pumice, and basalt.

* Minerals found in sedimentary rocks: The expedition also traveled through areas with sedimentary rocks, where they might have seen minerals like limestone, sandstone, and shale.

It's important to remember that Lewis and Clark weren't trained geologists. Their descriptions of rocks and minerals are often general and lack the scientific precision of modern studies.

If you are interested in the minerals specific to particular locations on the Lewis and Clark trail, you can consult geological maps and research papers from the regions. You might also find interesting information in the journals and accounts of the expedition members.