H. D. Holland’s research while affiliated with Princeton University and other places

Calcium carbonate was precipitated from sea water by the slow addition of dilute Na 2 CO 3 solutions. The distribution coefficient k Sr A , defined by the ratio of m Sr 2+ / m Ca 2+ in precipitated aragonite to m Sr 2+ / m Ca 2+ in the solutionfrom which the aragonite was precipitated, was found to decrease linearly with increasing temperature from 1·17 ± 0·04 at 16°C to 0·88 ± 0·03 at 80°C. Above 30°C aragonite was the only phase precipitated; at 16°C a calcite containing 8-10 mol % MgCO 3 commonly accompanied aragonite; at 3°C calcite containing less than 1 mol % MgCO 3 , vaterite, or CaCO 3 ·H 2 O were dominant phases, while aragonite was usually absent. It is shown that the value of k Sr A depends on the kinetics and mechanism of crystal growth, and that this must be true for all distribution coefficients determined under conditions in which the rate of crystal growth is greater than the rate of diffusion within growing crystals. Although the kinetic dependence of distribution coefficients limits the usefulness of the chemical composition of minerals in interpreting the chemistry of the environment in which they were formed, some distribution coefficients appear to be sufficiently insensitive to rates of crystal growth, so that their use is virtually exempt from this limitation.