Acquire an igneous rock. Look for fine-grained, dark-colored igneous rocks such as basalt or coarse-grained, light-colored igneous rocks such as granite. Granite, basalt and other igneous rocks form when molten rock cools, gaining their color and texture from the length of the cooling process.
Name your pet rock. Study its size, texture and color carefully to assist you in deciding on a suitable name.
Create a name plate for the display/housing. Use adhesive labels or a small cardboard plaque. Include a description of your pet rock on the name label that includes the igneous rock type, texture and color.
Determine and record your pet rock's family history. Use a magnifying glass to study the rock's particles. Smoother igneous rocks such as basalt or rhyolite cooled quickly and came from ocean basins, while more coarse rocks such as granite and diorite cooled slowly and came from land masses.
Provide your pet rock with natural-looking facial features. Attach small pebbles for the eyes and nose with strong craft glue. Use a small piece of twig or some raffia as the mouth.
Present your pet rock to an instructor or the class. Provide information about the rock's physical characteristics and the determinations you made about the rock's origins based on them.