Instructions
Brush away dirt, plant life or any form of obstruction to the surface of the rock so you can clearly discern its key characteristics. You can use water if you need to, but be sure to let the surface of the rock dry before identifying further, as water often darkens mineral colors and can misrepresent the texture of the rock.
The rock's texture will tell you whether the rock is igneous (little texture or layering, often made of black, white and grey minerals), sedimentary (made of sand or clay layers, often brown or grey with a softer texture), or metamorphic (straight or curved layers often with a variety of colors, grain sizes and appearances).
Examine the grain or particle characteristics of the rock. Are the pink bubbles large or small? Do they form a large part of the rock as a whole? What other colors are there? Are the bubbles smooth, rough, glittery, matte?
The hardness of the rock (whether it can scratch glass, how easy it is to break apart) can also help identify what kind of rock you have.