Table 2

Basic chemistry of the natural waters used in precipitation experiments and the resulting experimental mineral precipitates.
Sample
 Initial chemistry
 Final chemistry (6 weeks)


pH
 Cation (mg/L)
 System
 pH
 Cation (mg/L)
 Percent change
 Precipitate mineralogy
Ground water
 8.12
 Mg – 340
 abiotic
 9.2
 Mg – 352
 +3.5%
 no precipitate


Ca – 4.00

Ca – 4.48
 +12%


Si – 4.55

Si – 5.36
 +18%



biotic
 9.6
 Mg – 134
 -61%
 dypingite





Ca – 2.45
 -39%





Si – 1.73
 -62%
Wetland water
 8.58
 Mg – 780
 abiotic
 9.0
 Mg – 457
 -41%
 nesquehonite


Ca – 11.1

Ca – 6.25
 -44%


Si – 18.9

Si – 19.9
 +5.3%



biotic
 9.5
 Mg – 177
 -77%
 dypingite





Ca – 1.99
 -82%





Si – 0.16
 -99%
w/ NaOH

abiotic
 10.3
 -
nesquehonite w/ dypingite

Power et al. Geochemical Transactions 2007 8:13   doi:10.1186/1467-4866-8-13