Dolomite and Calcite Crystallites

During the fossilization process, mineral replacement often occurs, substances such as calcite and dolomite filling in pore spaces of hard parts or, in the case of petrification, actually replacing original organic matter. Abundant and widespread, dolomite and calcite, along with the closely related mineral known as aragonite, are believed to comprise about 15 percent of the sediments and sedimentary rocks on Earth. The most common of these carbonate minerals is calcite, which typically exhibits a hexagonal crystalline structure and is white or colorless in its pure form, although it is often found in various hues due to the presence of impurities, such as iron or manganese. A calcium magnesium carbonate, dolomite may also be white, but the mineral with a vitreous to pearly sheen may be gray, brown, or red as well.

© 1995-2022 by Michael W. Davidson and The Florida State University. All Rights Reserved. No images, graphics, software, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders. Use of this website means you agree to all of the Legal Terms and Conditions set forth by the owners.
This website is maintained by our
Graphics & Web Programming Team
in collaboration with Optical Microscopy at the
National High Magnetic Field Laboratory.
Last modification: Tuesday, Jan 06, 2004 at 10:31 AM
Access Count Since November 29, 1998: 30950
Microscopes provided by:
Visit the Nikon website. Visit the Olympus Microscopy Resource Center website.