Please try this MWE:
\documentclass{article}
\usepackage[garamond]{mathdesign}
\usepackage{roboto} % or another sans serif font, e.g. the cabin package
\usepackage{blindtext}
\begin{document}
Centred asterisk \textasteriskcentered, which is different from this one: *.
\end{document}
Different LaTeX installations I use compile this without the \textasteriskcentered, i.e. invisible. What is causing this and how could this be fixed? Note that you need to add the .pfb files from URW-Garamond to your path. If you disable the sans serif package, you get a \textasteriskcentered in a different (the default?) font than Garamond. Does this mean the .pfb files from URW-Garamond aren't the ones I need? Also, I wonder what other glyphs aren't showing up correctly. How do I use Garamond with mathdesign correctly?

exlength is directly proportional to font size, so this solution works for any font size setting. – Erik Mar 18 '15 at 21:17-.7exseems good too: the asterisk looks very nicely centred inx\textasteriskcentered x(between two x's), although the default font has a centred asterisk that seems bigger and raised a little higher. I'll adjust manually if the asterisk seems out of place in a footnote symbol next to other footnote symbols. By the way: why do you specify the height and depth of the\raisebox? If I set them to different values, nothing happens? And I can omit them too, nothing happens as well. – Erik Mar 18 '15 at 22:17