Theory 23/Crystal Growth
Morphology Is a Supersaturation Ratio
The claim
Crystal habit is set by the ratio of supersaturation to surface diffusion rate rather than by supersaturation alone, so the same solution can give needles or blocks.
01The mechanism
Faces grow at rates set by how fast material arrives versus how fast it spreads on the surface; the ratio determines which face outgrows the others.
02Predictions
- P1Habit should map onto the ratio.
- P2Supersaturation alone should mispredict across additives.
03Refutation
Habit tracking supersaturation would remove the diffusion term.