Silicon dioxide is the main chemical in glass....
The “journalist” should have used the term “glass like”..another example of how imprecise modern day journalists are.
Now it is possible that the brain was inundated with silica containing molten rock...and it turned the brain to “glass”
That’s sorta what some think about Lots’ wife....turning to “salt”
Yes, glassware would have been accurate. Lots of minerals will crystallize under the right conditions but are not glass. Obsidian is a form of rock, but it isn’t made of silicon-oxide.