Sedimentary Rock Examples

The table below shows examples of common clastic sedimentary rocks. They are listed by grain size in decending order. Grain size is one factor in classifying sedimentary rocks.Clicking on the name of the rock will bring up a larger picture and a description of the rock type in a new window.

Examples of Clastic Sedimentary Rocks

Conglomerate Conglomerate is made up of rounded pebbles cemented together.
Breccia Breccia is made up of angular pebbles cemented together.
sandstone Sandstone is sand grains cemented together into solid stone.
siltstone Siltstone is made from silt particles cemented together.

Shale Shale is made from silt particles cemented together. It is similar to siltstone but with even finer grain size,

The table below shows examples of common chemical sedimentary rocks. Clicking on the name of the rock will bring up a larger picture and a description of the rock type in a new window.

Examples of Chemical Sedimentary Rocks

Evaporates

Halite Halite is made when a body of seawater becomes closed off and evaporates. As the water evaporates it the remaining water can no longer hold the same amount of salt. The salt precipitates out and is deposited as crystallized halite or rock salt.
Gypsum gypsum is an evaporate made of calcium sulfate that has many forms. Clear flattened crystals are called selenite. Satin spar and alabaster are also common forms of gypsum.

Carbonates

Limestone Limestone is made primarily of calcium carbonate or calcite. The most common source of this calcite is the shells of marine organisms.
Fossiliferous Limestone Fossiliferous Limestone is limestone that contains the remains of ancient plants or animals in the form of fossils.
Siliceous Rocks

Chert Chert is a microcrystaline sedimentary rock that is silica rich. It has many forms and colors.
Organic Sedimentary Rocks

Coal Coal is composed of organic matter in the form of plant fragments. Coal can be:
Lignite is black and has a crumbly consistency.
Bituminous coal can be dull to shiny and black.
Anthacite is usually considered metamorphic

Sedimentary Rocks

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