One feature of compounds made with transition metals is their intense color. There are many examples in nature, including gemstones and paint pigments. Even the color of blood comes from the ...

Rubies are formed of a mineral called ... The color comes from additional traces of chromium and vanadium. Different trace elements can produce other colors, allowing beryl to form semiprecious ...

(THE CONVERSATION) The colors of rubies and emeralds are so striking that they define shades of red and green – ruby red and emerald green. But have you ever wondered how they get those colors?

Daniel Freedman, University of Wisconsin-Stout (THE CONVERSATION) The colors of rubies and emeralds are so striking that they define shades of red and green – ruby red and emerald green.