Biological mineralization strontium

WiLCOCK JR, Perry CC, Williams RJP and Brook AJ (1989) Biological minerals formed from strontium and barium sulphates. II. Crystallography and control of mineral morphology in desmids. Proceedings of the Royal Sodety of London B 238 203-221. 

The principal abiotic processes that transform strontium in soils and sediments are mediated by sorption and desorption reactions between the soil solution and matrix (precipitation, complexation, and ion exchange), and controlled by pH, ionic strength, solution speciation, mineral composition, organic matter, biological organisms, and temperature (see Section 6.3.1). 

The cations Sr and Ba concentrate in the vertebrate skeleton, and the amounts of these elements vary as a function of mineral stmcture. In vivo, strontium has been found to accumulate in bone by exchange onto crystal surfaces, and is rapidly washed out after exogenous strontium is withdrawn (Dahl et al. 2001). Incorporation of strontium into the crystal lattice as a substitute of calcium occurs at a low level in vivo, in contrast to the extensive lattice substitution of strontium for calcium in fossil bone. Strontium is not easily washed out of subfossil bone (Tuross et al. 1989), and the uptake of strontium into biological apatite was once proposed as a potentially useful chronometer analogous to fluorine uptake (Turekian and Kulp 1956). The combined uptake of strontium and fluorine into vertebrate calcified tissue may in no small part account for the existence of a fossil record. Both of these elements stabilize biological apatite, and add substantially to the crystal stability of apatite under acidic conditions (Curzon 1988). 

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