Calcium Carbonate Monohydrate in Seawater

Abstract

NATHAN¹ recently suggested that the vaterite form of calcium carbonate may be an indicator of lake water pollution. His reasoning is based on a recent report² which documents the presence of vaterite in lake water and on his own experiments in which condensed phosphates, taurates and other unspecified surfactants were found to delay the precipitation of calcium carbonate in solutions made supersaturated with respect to calcium carbonate. When calcium carbonate eventually precipitated (after a long delay), the crystal phase was reported to be vaterite instead of calcite, the usual form; Nathan did not, however, present his X-ray data. Nathan stated that the precipitate was comprised of a “soft” and “hard” form. The “hard” form (vaterite) adhered strongly to the glass beaker containing the solution.