So, in the last column (J) we have multiplied all the atom numbers in columns H and I by a constant factor so that the number of atoms of oxygen is exactly 8. Using the numbers in column H and the oxygen total of 2.977, we could write the formula of the feldspar as Ca 0.011Na 0.230K 0.132Fe 0.013Al 0.382Si 1.097O 2.977, but normal feldspar analyses are written with 8 atoms of oxygen. Columns H and I give the results of these calculations. To calculate moles of oxygen, we multiply the values in column G by the number of O in each oxide (column F). To calculate relative numbers of cations, we multiply the values in column G (moles of oxides) by the number of cations in each oxide (column E). The values in column G are relative values only they total to 1.486, which has no scientific meaning. To convert from % grams of oxides to moles of oxides, we divide the oxide weight % values (column B) by oxide atomic weight (column C) column G shows the results. Columns C, D, E, and F give chemical data for the oxides. Column A lists the oxides and column B gives the results of the analysis. The table below gives the chemical analysis of a feldspar from Grorud, Norway. Fortunately there are Excel spreadsheets and programs to do it for you. Normalization is a tedious but straightforward arithmetical operation when done by hand. Normalization is the process of converting an analysis into a formula. We normally report mineral analyses in values of oxide weight %, but mineral formulas are written in terms of numbers of atoms.
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