Skip to content
Skip to main content


Updated Thursday, 28th September 2006

A brief description of the nature of limestone

This page was published over 16 years ago. Please be aware that due to the passage of time, the information provided on this page may be out of date or otherwise inaccurate, and any views or opinions expressed may no longer be relevant. Some technical elements such as audio-visual and interactive media may no longer work. For more detail, see how we deal with older content.

Limestone is a fine to medium-grained sedimentary rock. It is usually grey, white, yellowish or tan. It can often be streaked red with iron or black with magnesium impurities. Limestone is made up of the mineral calcite, which fizzes in white vinegar.

It does not contain any visible crystals but it can sometimes look sugary.

Limestone typically contains fossil shells and corals which are themselves made up of calcite.


How is it formed?
Limestone can be formed by the burial of coral reefs, but mostly it forms from lime rich mud in warm tropical waters.

Get closer to geology



Become an OU student


Ratings & Comments

Share this free course

Copyright information

Skip Rate and Review

For further information, take a look at our frequently asked questions which may give you the support you need.

Have a question?