Almost all existing clay in Indonesia called “loam”. Clay is a natural product, namely hasilpelapukan that a large part of the earth’s crust consists of rocks feldspatik, such as granite rocks and igneous rocks. Before the move, the clay is a pure mineral found in rock solid heat and then dissolve. Soluble rock is no longer rock hard as the original but has been turned into soft rock and decomposed and discolored due to drift of water.
The results of these events are formed fine particles and mostly moved by water power, wind and glaciers to a lower place and away from source rock with a particle size that is almost the same, while others remain at the location where the host rock is located.
Figure 2. Source clay
Natural clay produces a continuous basis, so it is not surprising that the clay found everywhere and the numbers are very large. Indeed shape the earth’s surface is always changing, the mountains, valleys, rivers, benuabenua, islands and so are not in a moment, but it takes millions of years. The most natural clay mummies still contain free grains and ingredients of sand or dust.
Generally, these additional elements consist of quartz, feldspar, iron and so there is also an organic element Iainnya determine the properties of various clay and its use for certain purposes. Some properties of clay is a common trait to disintegrate in water, the color before and after burned, plastic before being burned, hard in a dry state, solid and strong after being burned.
Mineral-Mineral Skin formation of the Earth
The surface of the earth that we live in today is the result of cooling of the earth’s crust that covers the inside of the earth is still very hot (magma) .When the earth is still in a period of melting, heavy materials such as metals tend to settle into the deepest level. Because the deposition process, the chemical composition of the earth in all parts of the skin uniform approach. The more the earth cools, the top layer of skin called the Earth will condense and petrified.
Figure 3. Cycle rock formation
Rocks formed by the cooling process called igneous rocks (igneous rock). The chemical composition of the earth’s crust is composed of granite or igneous rocks to a depth of 16 km is as follows:
SiO 2 59.14
Al 2 O 3 15:38
Al 2 O 3 + FeO 6.88
CaO 5:08
Na 2 O 3.84
MgO 3:49
K 2 O 1:13
H 2 O 1:15
TiO 2 1:05
Other 0.90
What is interesting from a chemical analysis of the above is very little iron oxide or other metal oxides that form the earth’s crust, but rather elements of silica (SiO2) and alumina (Al2O3) most dominating forming the Earth’s crust.