Kristine, I think there's a nice paper in Pier de Groot's book, which you may want to refer to. But, basically, you need to adjust the pH to between 3 & 4, thereby preventing any bicarbonate [let alone carbonate] species from being present in the water. You should get a carbonate-free precipitate that way. On May 15, 2006, at 3:00 PM, Kristine Nielson wrote: > Under what conditions does BaCO3 precipitate? I ask because a while > ago I tried precipitating BaSO4 from gulf of mexico porewaters and had > a coprecipitate with carbon in it (at least, that's what the EA told > me), but everyone I asked claimed BaCO3 shouldn't precipitate at all. > I'm rather relieved to know the compound at least exists, and would be > grateful for any information on how and where it forms. > > Thanks, > > Kristine -- ************************************************************* Steve Nelson Associate Professor Dept. of Geological Sciences S-389 ESC Brigham Young University Provo, UT 84602 801-422-8688 "Guns don't kill people, Dick Cheney kills people." ************************************************************** Disclaimer for the feeble-minded: It should be painfully obvious, but the identification of my affiliation with Brigham Young University does not imply that the University endorses any political or otherwise partisan content of this message.