Rock Texture Effect

Step 1. Create a new file

Step 2. Create a New Layer. (Layer>New Layer)

Step 3. In this example we'll apply the texture to some text

Begin by selecting the Type Tool
Select the Type Mask Tool from the Options Palette up top.
Once you select the Type Mask Tool, you'll notice the background will turn a light red.

Step 4. Choose a font for the text

I selected Arial Black which is a large font that will work nicely with the texture.

Step 5. Type out some text

After you've made your type, select a color and fill in the selection. (Edit>Fill Foreground Color)

Step 6. With the type selected, create a New Layer on top of the current layer. (Layer>New Layer)

Step 7. On this new top layer, fill the selection with white

A quick way to do this is to click the D key once to set the foreground/background to their default colors and then click command-delete/control-backspace to fill with the background color of white.

Step 8. Add some noise to it

Go up to Filter>Add Noise... You can use my settings here or experiment with your own. Just make sure the Monochromatic option is selected.