Particles | Red in colour | Minerals | Birefraction |
l8 | + | biotite | slightly; but the birefringency is masked by sombre proper-tint of the mineral |
l11 | + | phosphorite clay, iron-rich | no |
l14 | lightly | a brick fragment | no |
l15 |
| calcite | + |
l17 | yellow-red | K-aluminosilicate | no |
l18 |
| a silica | no |
l26 | + | K-aluminosilicate | no |
l34 | at the top | a washing powder | no |
l38 |
| a wax | no |
l39 | + | hematite | no |
l40 |
| calcium carbonate | + |
l41 |
| quartz | no |