Gold like glass?

I've always thought this description it was odd:

‭Revelation‬ ‭21‬:‭18‬ ESV

"The wall was built of jasper, while the city was pure gold, like clear glass."       http://bible.com/59/rev.21.18.esv

But maybe the Romans understood the concept.  And if this kind of cup was used to detect purity – or warn of impurities that are present in what it contains – then the whole metaphor starts to get really interesting:

http://blogs.transparent.com/latin/ancient-roman-nanotechnology-improving-the-future/

Just an idea; not going to start a new denomination over it.  :)