This may be a bit more accessible than the PDF file I posted earlier.  It deals strictly with geometric shape characters in Unicode:  http://www.unicode.org/charts/nameslist/n_25A0.html

25CB begins a chunk of Circle characters including the one with top right quadrant filled in at 25D4
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Brian

A great many people think they are thinking when they are merely rearranging their prejudices.

         ~ William James