File talk:Corundum-3D-balls.png

Proportion of red to grey balls
The stick diagram has the proportion 2:1 of red-balls and grey balls. This does not seem to illustrate the formula AL2O3. A clarifying statement would be helpful. — Preceding unsigned comment added by 76.192.50.27 (talk) 20:09, 9 Oct 2010 (UTC)