Stills from the Star Trek episode "Miri" (1966), from Trekcore
And, for Orange Crate Art, who likes pencils, here's Miri (Kim Darby) herself, sharpening pencils. Are these Mongols?
[No. OCA informs me they are Dixon Ticonderogas. You can tell by the green stripes on the ferrule, he tells me.]
In the future, they write with plastic chopsticks on something like iPads? as we see here in the episode "Mirror, Mirror":