I've posted earlier discussions about chiral liquid crystal phases, and in particular cholesteric phases, and how they can arise from "doping" a small amount of a chiral material into an achiral liquid crystal. Similar things happen when you add a chiral (nonracemic) dopant into other kinds of liquid crystal phases: smectic A phases can be made in chiral smectic A* phases, smectic C into C*, etc.
Some interesting things can happen at the transitions between chiral phases. For example, at the transition from a SmA* to short-pitch N* (cholesteric), the frustration caused by these two phases can give rise to a new kind of phase, called Twist Grain Boundary (TGB) phases. The image shown to the right has been tentatively assigned as a TGBA phase, but requires further characterization
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As is so often the case, still images don't entirely get across the striking way in which these patterns develop. To the left is a short movie showing how the fibril texture grows in from the dark smectic A phase. At the end of the movie, the texture of the cholesteric phase appears.