Topaz, a mineral used both as a gemstone and for the manufacture of mullite, an important heat-resistant material used in dishware, as insulation for spark plugs, and for lining furnaces and boilers.
WHAT'S INSIDE: EARTH SCIENCE
According to the Bulletin of Atomic Scientists, it’s currently 5 minutes to midnight. It’s scarier when you know that midnight marks the end of life as we know it. What’s been nudging the time closer to 12?
Everybody agrees the Pacific is the big daddy of Earth's oceanic family, but how well do you know this enigmatic ocean? Test your sea legs by taking this quiz.