Halloween has passed, but the scares continue with this slippery substance: mercury! The faded label on this vial, acquired in a recent donation, says, “Mercury from thermometer.” Inside, a silver blob bounces back and forth when the vial is shaken. But what is this toxic liquid doing in a blog post from a mineral museum?
Before mercury’s health risks were well understood, it was used in a variety of electronics and instrumentation. Even today it is used in tiny quantities for white fluorescent lights and colorful neon signs. (Worried about exposure to mercury from a broken bulb? Don’t be–safe cleanup is easy to do.) And all the mercury we use is mined from ores that include minerals like cinnabar, or mercury sulfide.
Cinnabar has a vivid red color and commonly forms as a thin coating or granular aggregate on other rocks. It forms in hydrothermal systems like hot springs close to the surface of the earth, generally near volcanic centers.
This post is part of our What’s in the Box? series.