Is glass more dense than wood?

Yes. Glass and wood both vary greatly in density, but glass ranges from 2000 to 8000 kg/m3 and wood is only 350 to 1330 kg/m3 on average.

Sources here: engineeringtoolbox wood-density-d_40 and here: hypertextbook facts/2004/ShayeStorm (site won't let me link but I trust you can figure it out)

Whoever wrote this previous answer doesn't know what density is and should be ashamed of themselves:

In fact wood is believed to be more dense than glass. For example, if you were to side wood down a wood plank it would travel at a much slower pace than it would traveling on glass. This is because wood is much more dense than glass is.