Commonly found in #volcanic #rocks around the #world, moss agates are popular as ornaments and in the #healing #crystal industry. So-named because their branching forms resemble #moss and #ferns, the #gem’s materials are mainly made of manganese and iron oxides while the milky-white matrix of moss agate is a type of #quartz. #science #photoooftheday #volcano #earth #geology #rock 📷: Courtesy of Shutterstock