Particles in rocks can fit together in a variety of ways, depending on the type of rock and the minerals that compose it. Some of the most common ways that particles fit together in rocks include:

* Crystalline structure: In crystalline rocks, the particles are arranged in a regular, repeating pattern. This type of structure is found in many igneous rocks, such as granite, and in some metamorphic rocks, such as marble.

* Amorphous structure: In amorphous rocks, the particles are arranged in a random, disordered fashion. This type of structure is found in many sedimentary rocks, such as sandstone and shale.

* Porphyritic structure: In porphyritic rocks, there are two distinct sizes of particles. The larger particles, called phenocrysts, are embedded in a matrix of smaller particles. This type of structure is found in many igneous rocks, such as porphyritic andesite.

* Fragmental structure: In fragmental rocks, the particles are fragments of other rocks or minerals. This type of structure is found in many sedimentary rocks, such as conglomerate and breccia.

The way that particles fit together in rocks can have a significant impact on the rock's properties. For example, crystalline rocks are typically harder and more durable than amorphous rocks, and porphyritic rocks are often stronger than fragmental rocks.