In a previous color, we’ve talked about what makes things colored — the way objects absorb, reflect, or transmit light at different wavelengths. But let’s be a bit more specific. What gives gemstones ...

The world is awash with the color purple — lavender flowers, amethyst gemstones, plums, eggplants and purple emperor ... and short-wavelength cones detect blue. Related: What color is the universe?

Not every bride prefers a traditional diamond. More couples today are choosing engagement rings that feel personal and ...