Actually any igneous rock can be vesicular (have gas holes in it). But two types of vesicular igneous rocks are so common we give them special names. Both are light weight. They are differentiated on the basis of color and the size of the holes or vesicules. If your sample is not light weight with abundant vesicles, Go Back to the previous step.
| Dark colored, light weight, vesicles are large and obvious (CLICK HERE) | |
| Light colored, light weight, vesicles are quite small and may require a hand lens to be seen (CLICK HERE) |
| BACK TO STEP 1|
| IGNEOUS ROCK TEXTURES | MINERALS OF IGNEOUS ROCKS | IGNEOUS ROCK CLASSIFICATION |