IN-SITU ATOMIC-FORCE MICROSCOPE IMAGING OF CALCITE ETCH PIT MORPHOLOGY CHANGES IN UNDERSATURATED AND 1-HYDROXYETHYLIDENE-1,1-DIPHOSPHONIC ACID POISONED SOLUTIONS

Morphology changes in etch pits formed on the (1014) cleavage plane of calcite were induced by varying the ratio of [Ca2+] to [CO32-] in the bulk solution as well as through the addition of the crystal poison 1 -hydroxyethylidene-1, 1-diphosphonic acid (HEDP). Three distinct morph ologies were noted: symmetric rhombic, asymmetric rhombic, and triangu lar with a rough curved hypotenuse. The latter represents a transient morphology which is only observed during the actual dissolution proces s, while the former morphologies persist after dissolution is halted.