3 ms·

is there a concrete cutoff or shades of grey?

• maaku 15y ago
  I think what the GP is getting at is the chemical difference of ionic minerals (rock) vs amorphous collections of molecular compounds (i.e. water or methane ice). There is a categorical difference between the two chemically, although as an aside their properties in micro-gravity and the cold vacuum of the outer solar system are quite different from what you might have learned in your chemistry class.