There are many types of rocks. But did you know they only sort into four categories?! Here are the categories:

• Sedimentary Rock
• Igneous Rock:
• Metamorphic Rock
• Asteroid Rock

Each rock is unique and has its own properties and abilities. Here is how they form:

SEDIMENTARY ROCK:
A sedimentary rock forms when water and wind erode sediments to a body of water. There, the body of water compresses and mixes the sediments together. A sedimentary rock forms after that.

IGNEOUS ROCK:
An igneous rock forms when lava comes out of a volcano. From there, the lava rests down in an area until the volcanic eruption stops. Then, the lava cools down slowly and turns into an igneous rock.

METAMORPHIC ROCK:
A metamorphic rock forms underground due to heat and pressure. Here’s how it forms: If an igneous rock ends up underground, it is exposed to heat and pressure due to the Earth’s core. Then, it turns into a metamorphic rock.

ASTEROID ROCK:
Asteroid rocks are also known as asteroids. Some burn in the Earth’s atmosphere while heading for Earth. Some are large and hard to burn up in the Earth’s atmosphere. These rocks get smaller as they get closer to the surface. The ones that survived the atmosphere land on Earth.

Just to tell you, the top three rock types (Sedimentary, Igneous, and Metamorphic) are the ones on this list that originate from Earth itself. Asteroid rocks are different, and they originate from space.

There are five types of properties that define a rock:

• Color
• Hardness
• Luster
• Cleavage
• Streak

The color defines the color of the rock, there are many colors of rocks. For example: White, Brown, Black, Green, Red, Blue, etc.

HARDNESS:
The hardness depends on if you can scratch the rock with materials. If you use it to scrape glass and it scratches the glass, it is harder than the glass. If you use it to scratch steel and it doesn’t scratch the steel, it is less hard than steel. The hardness of the rock does NOT depend on how easy you can break the rock.

LUSTER:
The luster of the rock defines how it looks. For example: Pearly, Metallic, Dull, Glassy, etc. This is also important in defining a rock, because if a rock doesn’t have a luster, it is not defined as a rock anymore.

CLEAVAGE:
There is also Cleavage. Cleavage defines how it breaks when it breaks. For example, if you throw the rock very fast at the ground, it will probably break, depending on the type of rock. If it breaks and it turns into layers that are broken, this is an example of Cleavage.

STREAK:
The last one is Streak. Streak defines what color the streak is when you scrape it against something. For example, if the rock is harder than steel, and you scrape it against the steel, it will create a streak color depending on the rock and what its properties are. Not all outcomes are the same. If you scrape that same rock that you scraped on steel on glass instead, it may create a different streak color than last time. The streak color depends on the color of the rock, the type of rock, and its properties.

I hope you learned something in this post! If you didn’t fully understand it, you can put a comment below OR try reading the post again!