Igneous Petrology of Cape Granites

Biotite mainly changes with finer chlorite and occupies 10% of the rock and white mica and cordierite are less abundant (in most cases, cordierite does not exist) (Harris et al. , 1997). Biotite is the main body of most auxiliary minerals such as zircon and apatite (Scheepers & amstrong, 2002). Biotite and co-site are the most abundant ferromagnetic minerals in S-type garnet. Biotite and cordierite are decomposed into garnet by contradictory melting in these areas, so wealthy areas are rich in garnet (see Fig. 2) (Villaros, Stevens & Buick, 2009; Harris & Vogelli, 2010). The ground is surrounded by residual biotite surrounded by Cordelite (Harris & Vogell

Garnet stone usually exists as a mineral in igneous rocks such as granite. Many people are familiar with the Armandering Net as it is seen as a crimson crystal of igneous rock which is sometimes used as a granite counter top. Spessartine is an orange garnet seen in granite pegmatite crystals. Pyrope is a red garnet brought to the surface of the earth by a part of a peridot torn from the mantle during a deep volcanic eruption. Garnet is also found in basalt lava flow. Garnet is a relatively durable mineral. When rocks in garnet are weathered or eroded, it is often that they concentrate on soil and sediment. These alluvial garnet stones are easily mined and removed mechanically from sediment / soil, so they are usually subject to mining work.

Garnet rocks formed by rocks are most common in metamorphic rocks. Some occur in igneous rock, especially granite and granite pegmatite. Garnet stones from these rocks occasionally appear in clastic deposits and sedimentary rocks. A typical example of a typical sequential garnet is shown in the table. Garnet stone usually contains many inclusions, ie fragments of other rocks and minerals. Windmill garnet and snowball garnet may be used for garnet where inclusion appears to rotate. These garnet stones occasionally appear in the pyramid metamorphic rocks. Although their existence in different rocks has been explained differently, today's consensus seems to represent rotation during growth under dynamic metamorphic conditions, including pressure differentials.