The makeup of Earth is rocks-from the highest peaks to the deepest troughs. Through rock collecting, it has been discovered that there are different types of rocks and minerals that comprise our planet. Majority of the rocks on the surface are materialized from only eight elements. These are oxygen, silicon, aluminum, iron, magnesium, calcium, potassium, and sodium. The combination of these elements is what makes rocks different from each other.

If there is one thing that changes constantly, it is rocks. When wind and water break them down, the small particles get carried away and settle in a body of water to eventually harden into rock again. The Earth is at least 4.5 billion years old and the oldest rock that has been found dates 3.9 billion years old. Since rocks continually change, those rocks that are older than the oldest rock found have evolved into newer kinds of rock. The history of the Earth gets to be understood through the story of the rocks.

Experts have classified rocks according to how they are formed. These classifications are igneous, sedimentary, and metamorphic rocks. In starting your own rock collection, you should understand how the geologists categorize rocks. Let us now delve on each one:

Igneous rocks developed from melted rock or magma that has cooled down and solidified. The rocks melt due to high pressure and high temperature. When a volcano erupts, it spews out molten rock. It is the different cooling rates that gave rise to the subtypes of igneous rocks such as obsidian, granite, basalt, and andesite porphyry, to name a few.

Sedimentary rocks are layered accumulations of sediments (hence, the term) of rocks, minerals, or animal or plant material. These particles come together through the action of minerals and chemicals, while some are held together through electrical attraction. Since the layers are parallel to the Earth’s surface, you can deduce that any twist or break in the layering may have been caused by the Earth’s movement.

Metamorphic rocks are formed from sedimentary and igneous rocks that have been subjected to high pressure and temperature. The rocks do not melt, they just transform into denser and more compact rocks. The pressure and temperature can also transform metamorphic rocks into new forms.

A good rock collection represents the different types and subtypes of rocks. It should be labeled properly to distinguish one from another. Your collection need not be stagnant-that is, you can continually add new specimens or replace the old ones with better rocks. This way your collection is growing and will be more interesting. You can start picking up rocks from nearby surroundings. Next thing you know you will be traveling far and wide exploring the land for fascinating rocks that you can add to your set.

Training the eye to see the unique characteristics of each rock category will greatly enhance your rock collecting abilities. You will find that as you learn more techniques, the easier it will be for you to distinguish one from another.

Related posts:

1. You Should Learn Know How to Identify Rocks Before You Start Rock Collecting
2. Types of rocks, a rock collecting basic
3. Why on Earth Rock Collecting?
4. Know how to identify your rock collection specimens
5. Rock collecting can be addictive