Sedimentary rocks are formed through the accumulation and consolidation of sediments. These sediments can come from a variety of sources, including weathering and erosion of pre-existing rocks, deposition of organic matter, and chemical processes. As these sediments are deposited and buried over time, they undergo compaction and lithification, resulting in the formation of sedimentary rocks.

One characteristic feature of sedimentary rocks is the presence of distinct layers or beds. These beds are formed as new sediments are deposited on top of older ones, creating a stratified structure. Within these beds, minerals can be found occurring in various ways.

Cracks and Crevices:
Cracks and crevices in sedimentary rocks can provide spaces for mineral deposition. These openings may occur due to the drying and shrinking of the sediments during the lithification process. Minerals can then precipitate and fill these cracks and crevices, forming mineral veins or fillings. This process is known as veining.

Faults:
Faults are fractures in the Earth's crust where rocks on either side have moved relative to each other. They can occur during tectonic activity or as a result of other geological processes. Faults can play a role in the formation of sedimentary rocks by creating spaces for mineral deposition. Minerals can precipitate along the fault planes, resulting in fault fillings. These minerals can be different from those found in the surrounding rock layers.

Beds or Layers:
The primary occurrence of minerals in sedimentary rocks is within the beds or layers themselves. Minerals can be present as individual grains or as cementing material binding the sediment particles together. The mineral composition of sedimentary rocks varies depending on the source of the sediments and the depositional environment. Common minerals found in sedimentary rocks include quartz, feldspar, clay minerals, calcite, and iron oxides.

In conclusion, minerals occur in sedimentary rocks primarily within the beds or layers. They can also be found in cracks, crevices, and fault fillings. The mineral composition of sedimentary rocks is diverse and depends on the source of the sediments and the depositional environment.