Immunoprecipitation

In lieu of the impending snowstorm today I went into the Wii Weather Channel and saw a weather icon I hadn't seen before. It turns out that Rankin Inlet is experiencing diamond dust. Wow, that sounds pretty intense. Are there sharp crystallic fragments of ice blowing around outside? What did they do to upset Shiva?

As it turns out, diamond dust is kind of like fog, but instead of being a cloud of water droplets, it is composed of a cloud of ice crystals.

Diamond dust is similar to fog in that it is a cloud based at the surface; it differs from fog in two main ways. Generally fog refers to a cloud composed of liquid water (the term ice fog usually refers to a fog that formed as liquid water and then froze, and frequently seems to occur in polluted valleys such as Fairbanks, Alaska, while diamond dust forms directly as ice). Also, fog is a dense enough cloud to significantly reduce visibility, while diamond dust is usually very thin and may not have any effect on visibility (there are far fewer crystals in a volume of air than there are droplets in the same volume with fog). However, diamond dust can often reduce the visibility, in some cases to under a mile (1600 m).

Source

The sunlight reflecting off all of the tiny ice crystals into your eye causing glittering flashes of light results in the term "diamond dust".

On a related note, it turns out that Rankin Inlet was competing with Iqaluit to become the official capital of the territory of Nunavut, but we all know how that turned out : (