Natural stone as stair covering

Hello everyone,

today the exposed screed is being laid in our hallway and we are now looking for ideas on how to design our concrete pedestal staircase (straight run, landing, straight run in the opposite direction).

[*]We have excluded wood because the shoe cabinet for my office shoes will be in the basement and I will frequently walk up and down there in the corresponding high-heeled shoes
[*]We do not find small-format tiles particularly nice, as we would like the steps at least to be without joints.
[*]We were advised against large-format tiles, i.e. at least 90 cm long (like the steps), because cutting them is very time-consuming and thus costly
[*]so we ended up with natural stone

We would like the staircase to be similar in color to the gray exposed screed, so we have chosen "Basaltina" on site, which is probably one of the most expensive stones. Does anyone have any ideas regarding gray natural stones that are not too busy?

Or maybe completely different ideas?

We don't have a self-leveling screed, but gray tiles.... However, I don't find a contrast bad and therefore we went for a dark stone (Basalt Nero).