Crystal habit and growth conditions of brushite, CaHPO4 ⋅ 2H2O
1993; Elsevier BV; Volume: 131; Issue: 3-4 Linguagem: Inglês
10.1016/0022-0248(93)90183-w
ISSN1873-5002
AutoresF. Abbona, Finn Christensson, M.Franchini Angela, Hans Madsen,
Tópico(s)Minerals Flotation and Separation Techniques
ResumoBrushite, a polar compound, has been grown from aqueous solutions at 25 and 40°C in a large interval of concentrations, pH and supersaturations. The great variety of morphologies (aggregates, twins, regular and irregular crystals) are described and related to the growth conditions. The polar habit of brushite appears only under definite conditions. Four types of twins have been found, one of them occuring only at 40°C. The experimental crystal habit is compared to the theoretical crystal habit derived from the structure by the periodic bond chain (PBC) method. The form {111}, which has a high frequency, shows morphological instability due to its S character. The role played by the wrong incorporation of HPO2-4 in the kinks in forming the [010] twins and the irregular crystals is pointed out. The growth mechanisms of the most important faces are also discussed.
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