Subscribe Now! National Geographic Magazine $15
Visit our Online Shops

Sign up for free

Newsletters

Once a month
get new photos
and expert tips.

Tourmaline Starburst

Photo: Red tourmaline
A starburst or red tourmaline stands out against its white surroundings. Tourmaline is the name for a group of related minerals; red tourmaline also can be called rubellite. Semiprecious gemstones, tourmalines belong to a family of borosilicate minerals. They come in a range of colors from red to black and are found from Madagascar to Maine.
Photograph by Scott Camazine/Alamy

Earth Topics

SPECIAL ADVERTISING SECTION

Photo: 2009 Winner

Photo Contest

Find out who takes home the Grand Prize!

Photo: Glass of water

Take Quiz

Test your water knowledge.

Six Degrees Book and DVD

Image: Cover of Six Degrees: Our Future on a Hotter Planet

Get an eye-opening warning of the dangers of climate change, one degree at a time.

Forces of Nature

Photo: A volcano erupting

Guide to the most powerful forces on Earth: earthquakes, volcanoes, hurricanes, and tornadoes.

Support Conservation

Photo: Two penguins

Help conserve the world's natural resources.