Secondary standard
NOTES: Homogeneous.
 |  |
| Position | 56 |
| Mineral | Cordierite |
| Sample Name | Cord |
| Type | Ring silicate |
| Nominal formula | Mg2Al4Si5O18 |
| Supplier | Cannon Microprobe, Seattle, WA |
| Source | Brazil (?) |
| Original reported analysis | Calculated from ideal formula |
| Composition quality | Secondary standard |
| Comments | Analysis shown is based on EDS and stoichiometric constraints. No Mn, evidence of Fe3+, or Na in channels. |
| O Mg Al Si Fe | 48.58 7.17 18.2 23.69 2.36 |
