The colors of rubies and emeralds are so striking that they define shades of red and green—ruby red and emerald green. But ...

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

Like their gemstone cousin the sapphire, rubies are just a variety of corundum, or aluminum oxide ... was rewarded with a large, deep pink ruby. This looks like a fun, quick little project ...

Rubies are a red variety of the mineral corundum, which is essentially aluminum ... The intensity of a ruby’s red color can vary based on the concentration of chromium. In fact, the most prized ...