Non-carbonate particles are part of the grain assemblage in many limestones and dolomites. These grains may be siliciclastic debris, such as quartz, feldspar, or lithic fragments, derived from outside the basin of deposition. The entire range of grain types that appear in sandstones can be mixed into carbonate rocks. Alternatively, there may be grains of phosphate, iron oxides, or glauconite that form by chemical precipitation within the basin of deposition. Even where abundant, neither type of non-carbonate particle enters into either the Folk or Dunham classifications. If non-carbonate particles are quite noticeable, they can be mentioned in a supplemental descriptor, for example, "glauconitic echnioderm grainstone" or "sandy biomicrite". An abundance of non-carbonate particles of intrabasinal origin is usually an indicator of slow rates of sediment accumulation.

Non-carbonate minerals also occur within the authigenic portion of limestones. Examples of these are are included in the cements section.

Click the thumbnails for examples below to open a larger view of the image; once they are opened, some of the enlarged images can be toggled between plane-light and cross-polarized views with a mouse-over.