I bet that most of you who haven't seen this website shared already haven't heard of a sea sapphire (I hadn't). They are copepods (shrimp-like sea animals) just a few millimeters long that can be found in several of the world's oceans. Males float in the water and look like a shimmering, glowing, iridescent sapphire due to extremely thin crystal plates in their cells. These plates are separated about the distance of the wavelength of blue light, so they only reflect back a blue color through their transparent bodies. They appear to flicker on and off, and Japanese fishermen even named the sight of thousands of them at the water's surface “tama-mizu”, or jeweled water.
http://deepseanews.com/2014/02/the-most-beautiful-animal-youve-never-seen/
http://deepseanews.com/2014/02/the-most-beautiful-animal-youve-never-seen/
Photo credit: Stefan Siebert