Mary E. Thompson

Magnesium in sea water: an electrode measurement.

Magnesium ion in standard I.A.P.O. sea water was measured with a magnesium-sensitive electrode. The results, presented either as magnesiumion activity (0.017) or as the amount of ionized magnesium (0.048M or about 90 percent of the total magnesium), agree well with the data from the chemical model for sea water proprosed by Garrels and Thompson.

Simplotite, a new quadrivalent vanadium mineral from the Colorado Plateau

„ „....* ,., „ Introduction and acknowledgments 5 Occurrence 6 Physical and optical properties 8 Chemical analysis 9 X-ray data 11 Literature cited 18 Figure 1* Index map of parts of Colorado and Utah, showing the localities of simplotite 7 2» Electron diffraction spot pattern of simplotite representing the a*-c* reciprocal net plane superimposed on an aluminum ring pattern 15 3. Schematic drawing showing relation between reciprocal lattice, optical orientation, and habit of simplotite ;..» 1?