Thanks for your input Eric Blank, some very good points there!
There are a few different colored varieties of pyropes (ranging from black, brown, red, orange, and yellowish). Not a big deal though. They could all be merged into a single fire-eye garnet entry to reduce clutter, which is both good and bad I suppose (less clutter in the menus, but less variety in the game).
I disagree on merging chert with sandstone (they are very much different types of stone, chert is a basic chalcedony-primary rock, could possibly rename it to flint for new players, but that's a little disingenuous), but I am totally onboard with merging the variations of clay/mud/silt stone into one family (siltstone maybe). Same with the lava-derived extrusive stones. Rhyolite ---> pale lavastone, Andesite ---> coarse lavastone. Remove Dacite (merged into rhyolite and Andesite). Keep Basalt unchanged.
Kaolinite would become the new claystone, indicating its use in making ceramics (porcelain).
You also hit the nail on the head with the variations of gypsum. They are extremely redundant, describing only slightly different crystalline structures of the same mineral. Best to just merge them into Gypsum host mineral, and use satinspar as gemstone quality gypsum. Also, anhydrite is in the vanilla game, but is not gypsum reaction class, which is totally silly, because anhydrite IS the plaster material made from gypsum! That's definitely getting a fix, or just getting removed.
Calcite could totally be "clear marble", thats not half bad. If I were to keep to an actual (old-world) naming convention though, it might more properly be calcspar, limespar, icespar, limeglass, or crystal limestone.