Argillaceous minerals

Argillaceous minerals are minerals containing substantial amounts of clay-like components (Greek: ἄργιλλος = clay). Argillaceous components are fine-grained (less than 2 µm) aluminosilicates, and more particularly clay minerals such as kaolinite, montmorillonite-smectite, illite, and chlorite. Clays and shales are thus predominantly argillaceous.

Additional recommended knowledge

Don't let static charges disrupt your weighing accuracy

Safe Weighing Range Ensures Accurate Results

Guide to balance cleaning: 8 simple steps

The adjective "argillaceous" is also used to define rocks in which clay minerals are a minor but significant component. For example, argillaceous limestones are limestones consisting predominantly of calcium carbonate, but including 10-40% of clay minerals: such limestones, when soft, are often called marls. Similarly, argillaceous sandstones are sandstones consisting primarily of quartz grains, with the interstitial spaces filled with clay minerals.