Comment on Pens in Space
it hasn’t been graphite for while now either….
pencil lead
Chalk isn’t chalk?
Regular chalk is calcium carbonate. Crayola’s website says their sidewalk chalk uses calcium sulfate (gypsum as an ingredient in plaster of paris).
So they’re both calcium salts.
no
Vespair@lemm.ee 10 months ago
Chalk isn’t chalk?
Arcka@midwest.social 10 months ago
Regular chalk is calcium carbonate. Crayola’s website says their sidewalk chalk uses calcium sulfate (gypsum as an ingredient in plaster of paris).
So they’re both calcium salts.
xor@lemmy.dbzer0.com 10 months ago
no