| In igneous rock the ore-bearing solutions may have altered the wall rock to a dense mixture of quartz, sericite, and chlorite. |
| Sericite is fine-grained muscovite formed by alteration of such minerals as feldspar, cordierite, and sillimanite. |
| At some locations sericite completely pseudomorphs topaz and the feldspars. |
| There is also a small amount of hematite, pyroxene and sericite. |
| This rock unit, along with a thick sequence of supracrustals, forms the hanging wall to a quartz sericite altered mylonite zone. |
| A dark compact rock, in which calcite and sericite predominate. |
