Density & Cleavage


Density is the weight of an object compared to it's size. The formula is mass divided by volume. Mass is found by using a triple beam balance. In the picture you can see two things that move across and mark the different numbers. Starting with the bigger of the three that one shows hundreds. Then you do the middle size which goes by tens. Finally the smallest one which goes by ones. Then you add them all together to find the mass. To find volume you use a graduated cylinder and sometimes an overflow can. In method 1 you measure how much water there is in the cylinder. Then drop the rock into the cylinder and measure the water level again. After that you subtract the two numbers and there you have the volume of the rock. Method two is when you have an odd shaped rock that cannot fit into a graduated cylinder you put it into a overflow can. First, you fill the can with water. Then, you put the rock in. Lastly, you find how much water came out in the overflow can.

Wikipedia image
Wikipedia image

Cleavage and Fracture

Cleavage and fracture is the way a mineral breaks. There are two different types of breakage. Hence the title the two different types are cleavage and fracture. The difference between cleavage and fracture is that when a mineral is fractured it has no pattern when breaking. With cleavage there is a pattern. There are two types of fractures one is uneven and the other is conchoidal. There are 3 basic types of cleavage: basal, rhombic, and cubic cleavage. Below is a video to tell you more about each one. If you start the video at 6:45 it will start talking about cleavage and fracture.

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