Opals! Photonic crystals! Structural color! Opals are examples of natural photonic crystals. They are composed of small silica nanoparticles ranging in size from 50-300nm, and packed tightly together ...

When the holy water accidentally splashes her opal hair clasp, the stone fades to black, leaving it as “colourless as a common pebble.” Lady Hermione collapses in pain and is reduced to ...

Opals are unique gemstones known for their vibrant colors ... revealing that it consists of different types of nanospheres and has a poorly crystalline nature. Using synchrotron X-ray diffraction ...

Narrator: High-quality black opal can cost over $10,000 per carat, making it one of the world's most expensive gemstones. But mining black opal isn't easy. After investing tens of thousands of ...