Rutile and tourmaline are two common minerals that quartz can grow around without interruption of the formation process. Another way inclusions can occur is when silicon-rich solutions enter a cavity that had prior crystal growths. This can occur over long periods of time (in some cases, millions of years) and in waves, sometimes resulting in quartz that displays multiple layers of zoning (phantoms). The quartz crystal continues to grow, provided the environment is still favorable, resulting in the foreign particles becoming enclosed by the overlying quartz formation. Once these particles have a moment to settle, in some cases they’ll settle on the quartz crystal. This can occur by movement of surrounding rock or just an overall change in the flow solution. Quartz with inclusions - Inclusions often occur when foreign particles find their way into the silicate-rich solution. Based on the structure and potential inclusions within the crystal, a lot can be learned about the history of its formation. The type of formation of a quartz crystal is most often dependent on the environment in which it grows. The necessary minerals for quartz formation precipitate into these cavities, depositing crystals (most often in an even layer) along the inner wall of the geode. Quartz formation within a geode - While there is yet to be a conclusion as to how geodes form, it's widely accepted that they form by means of solidification of gas bubbles (vesicles) within basaltic lava during igneous rock formation and in round cavities within sedimentary rock. In some instances, a surplus of these minerals will result in a solid vein of quartz where individual crystals can no longer be identified by the naked eye. The crystals will continue to grow as long as they're provided with the environment necessary for formation.

Long crystals, also known as spears, can form in these cavities when the solution drips more from one location of the rock than the other, explaining why vugs often form a wide variety of crystal sizes in close proximity. Quartz formation within a vug/cavity - Silicon-rich solutions will deposit themselves along the walls of the rock cavities. These cavities most often occur by means of tectonic activity, hollow tubes formed by lava, dissolution (breakdown of rock resulting in cavities) or even as solidified bubbles of gas within the earth (geodes). In this environment, the silicon atoms will bond to oxygen and begin building layers that over time result in cavities lined with thousands of crystals. This combination typically occurs when water that's high in silicon content (often gained through the breakdown of the surrounding rock) seeps through cracks in rocks and ends up exposed to oxygen within cavities. Quartz is primarily made up of two elemental components, silicon (Si) and Oxygen (O), both of which are in high abundance on our planet.

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