Infrastructure construction on coastal areas such as ports, bridges and airports require ground improvements when marine soils contain soft ground which includes fine grains in general. Fine-grained soils consist of clastic or non-clastic grains. Based on the mineralogy of soils, compressibility of soils shows different behavior. Fine-grained clay mineral soils show plastic and time-dependent deformation due to consolidation during constructions while silty soils without clay minerals show low compressibility. However, biogenic soils such as diatomaceous earth are more compressible than other silty fine-grained soils. Although fine-grained soils with clastic minerals and biogenic minerals are classified as silt, the behavior of clastic soils are less compressible compared to biogenic soils which have inner pores. We conducted one-dimensional consolidation experiments to investigate compressibility of diatomaceous earth and non-plastic mineral fines such as silica silt. The coefficient of consolidation, and volumetric compressibility are estimated, and show that the trends of diatomaceous earth properties are different from other silty soil properties based on the consolidation tests. We found that particle breakage plays a crucial role in compressibility of diatomaceous soils. While the compressibility of diatomaceous soils is similar to clastic soils at low stress, the differences in compressional behavior between two soils are distinct at high stress. The diatomaceous earth shows time-dependent compressibility due to creep or secondary compression by particle breakage process. Thus, settlement analysis should include the impact of morphology and mineralogy of fine-grained soils.