They are very fine
particles and they form as weathering products.
They can absorb and
eject water quickly, which makes them useful minerals.
They are magnesium and
silicates, and they are often found in fine grained metamorphic
(phyllite, slate) and sedimentary (siltstone, mudstone, shale) rocks.
is most often green but can also be brown, yellow or white. It forms as
a weathering product from minerals like garnet, biotite, amphibole and
pyroxene. It is often found in rocks like phyllites and schists. It is
most often massive in habit but can also form crystals and flakes.
is a group of minerals that include kaolinite, halloysite, dickite, and
nacrite. It is a very common mineral that is found in most soils and
rocks, and in most clay it is present.
is the softest of all minerals, easily identified as you can scratch it
with a fingernail. It feels soapy and is greay or white in colour. It
is often found in rocks like gabbros and peridotites, where it forms as
an alteration product from minerals like pyroxene and olivine.
is also a group of minerals containing lizardite, antigorite,
chrysotile. It forms in rocks like dolomite and peridotite when
magnesium silicate minerals alter.