What is neither a liquid nor a simple solid, and neither a crystal nor glass?
So what the heck is "q-glass"?Edit
The round nodules in this photo are q-glass - an unfathomable substance that defies current classification as either crystal or glass solid. In this aluminum, iron, and silicon mixture, the q-glass nodules are formed by using up iron and silicon. This concentrates the aluminum until it forms crystals - the long bright lines emanating from the nodules.
Stunning, no? Trouble is, the National Institute of Standards and Technology (NIST) doesn't know what this substance is, or how it's formed. And they suspect there may be more kinds of this stuff too. What they do know, is that, as the mixture is rapidly cooled, the nodules are formed outward from a seed, as seen with crystals. But X-rays diffracting light show that its atoms have no rotational or translational symmetry, as seen with glass. Still, the atoms are far more organized than in glass. Thus the name "q-glass" because it seems like quasi-glass.
Confused yet? You're not alone. For the juicy details, check out the research article by Long et al. (2013) in Physical Review Letters here , or read NIST's Tech Beat report by Michael Baum here. Another neat example of nature's provocative microstructures.