I figure this section would be better and more correct than the "Cryptocrystalline" for Obsidian?
But just wanted to post some pictures of this awesome wavy piece with a polished front. All the little white spots are pieces or minute pockets of another type of quartz, maybe Tridymite or Cristobalite.
I was looking for "Fire" in some of those shiny streaming veins for cabochons but don't want to destroy the piece looking for it. I'd call the whole piece Fire Obsidian. 

Nice fire.  I love the waves!