Students should make Homemade Stones about 1 week in advance of this lesson.

Geologists study earth materials called stones. Geologists have discovered over 200 different kinds of stone that form the earth’s crust.

One of the challenges a geologist faces is to determine the ingredients in different kinds of stone. Many earth materials combine to make stone, just as the ingredients you have in your kitchen can be combined to make cookies. Once a geologist knows a stone’s ingredients, he or she can generate ideas about the origins of the stone.

After making observations of the whole stone, a geologist physically breaks the sample apart into its different components. To make more detailed observations of the stone materials, the geologist may take it back to a lab where other equipment is available to perform chemical test on the stone. These tests provide more clues to the identity of the materials and evidence about how the stone was formed. Geologists observe the properties of stone. A property is something you can observe about an object, such as color, shape, and texture.

Activity Number 1: Physical properties of stone

Trace the stone onto the grid paper.

Using the magnifying class and by just looking at the stone, have the students write down as much as they can about the stone's properties.

Using the scale and tape measure have the students record:

Weight of the rock - how heavy the stone is

Diameter - distance across the stone

Circumference - distance around the stone

Depth - distance through the object

Activity 2: Real stones are made of up different components.

Break the stones in half. Using the nail as a type of geologist’s tool, use the nail to take the stone apart. Students should separate the ingredients into paper cups. Students should write down the different ingredients they find.

Some physical properties used to identify minerals are: