Do you know what are rocks made of? You cloud answer this question by just saying that rocks are made of minerals. But the question: what are minerals made of? And the answer might be that the basic component of a mineral is a crystal, and so on.
In the end, we see that rocks are made up of the elements. You have read of the elements in a previous question, and they include oxygen, silicon, and aluminum.
Rocks are made up of materials formed by the elements joining together in chemical combination. Some elements, such as gold, do not need to combine with other elements and can exist alone in the Earth’s crust.
But silicon, for example, can combine with oxygen in the proportion of two atoms of oxygen to one of silicon to form the compound called silicon oxide or silica. In nature, silica may be found as the mineral called quartz. Quartz may occur in a variety of colors depending upon the impurities it contains, ranging from black or pink to glassy clear.
You might find quartz as irregularly shaped broken lumps, but if you look at the pieces closely, they are more likely to have straight edges or may end in a pyramid shape. In fact, if the conditions informed. What you see is the result of many crystals growing and interfering with each other.
A crystal is a symmetrical solid. It has flat surfaces that have a direct relationship to the arrangement of the atoms in the crystal. A mineral may then be described as a solid, inorganic substance occurring naturally in the Earth’s crust, and having a definite composition and a structure which is consistent throughout.
In this definition, the word inorganic may be puzzling. It is a chemical term implying that the rocks do not contain the element carbon in the types of combinations which are normally associated with living creatures, or their basic materials.
This brings us back to the first definition in this question: that a rock is a mass of minerals. Unfortunately, nature is rather fickle and as you will find in many of the other natural subjects, the scientific definitions do not always tell the whole story. Some rocks have been formed by the action of living creatures and still others, such as volcanic glass, are not made up of crystals at all.
You May Like Also:
- Which Rock Burns?
- Can Rocks Breaks?
- How Many Types of Rocks are there?
- What are Rocks made of?
- Facts about Rocks and Soils
- Can a Rock Rot?