In the prior three chapters (Chapters 7–9), we addressed many aspects of minerals and rocks of igneous origin. They are the result of crystallization from a liquid magma over a wide range of high temperatures (~1400 to 600°C) in an environment in which oxygen gas (O2) is nonexistent and in which H2O is generally a minor constituent. This chapter deals with minerals that (1) are newly formed as a result of chemical reactions (under atmospheric conditions) that slowly destroy earlier minerals (e.g., feldspars) and recombine various ions in solution in water to form clay minerals, and oxides or hydroxides, and (2) those that are chemical precipitates in depositional basins such as carbonates, evaporite minerals, and Precambrian iron-formations. However, we must also mention those minerals that have survived the physical and chemical weathering processes while exposed to the atmosphere; these are known as detrital minerals.
We systematically treat 13 sedimentary rock-forming minerals. These include ice, the solid form of H2O; a hydroxide; a clay mineral (representative of the large clay mineral group); two polymorphs of CaCO3; four more carbonates; two halides; and two sulfates. Clearly, this group of common sedimentary minerals is totally different from the igneous rock-forming minerals discussed in Chapter 7.