Contribution to the habit of hydrothermally grown corundum

Abstract

Dedicated to Professor Georg MANECKE on the occasion of his 66th birthdayThe growth of corundum crystals without the influence of extraneous ions was achieved by the treatment of single crystals of topaz with supercritical water. The result is in agreement with previous calculations and considerations of other authors. A review of the different indexation of the corundum lattice is given.Korundkristalle wurden durch Behandlung von Topas-Einkristallen mit uberkritischem Wasser erhalten. Die Ergebnisse bestatigen die Berechnungen und theoretischen ttberlegungen anderer Autoren. Zusatzlich wird ein merblick uber die verschiedenen Arten der Aufstellung und Indizierung des Korundgitters gegeben.

Morphology and Structure of Solid Acids

“…The final indexing has to be accomplished by trial and error, while theoretical values can be taken into account once the crystal axis ratios and the crystal axis angles have been determined. More details on this SEM observation technique of microcrystals can be found in references [4,5].…”

Principal Ideas of Crystal Growth

“…(217)(218)(219)(220)(221) Finally, the method is now being actively used for predictions of growth morphology, and experiments essentially confirm its validity. (222)(223)(224)(225)(226)(227)(228) The theory of Wulff, as weil as the related contributions considered above , being of a thermodynamic nature, predict equilibrium shapes given surface free energies or binding energies of building units . Another approach, the statisticalmechanical theory of equilibrium crystal shapes, has recently attracted much attention (e.g., see references 229-232; for a review, see Rottman and Wortis (233)).…”