Sapphires???

[Rivarat]

I was given these to facet the other day by a jeweller friend. One of his customers wanted them faceted.
We were a little sceptical on the brighter blue.
Things didn't add up when I weighed the darker one, I though it should weigh around 7ct but came in at 4.5ct. 
So a scratch test on the darker one - scratched by quartz
SG test darker one 2.64. lighter one 2.55

So defiantly not sapphires, So are there any other options they could be?  I'm thinking glass as the are nice even colour whichever way they are rotated.

It would be nice to give his customers some good news, rather than just glass.

[swirly]

interesting looks like glass.any round bubbles.

[Pete49]

call it blue silica. 
Pete

[Rivarat]

No bubbles - nice and clean probably too clean.
The guy got them off an old friend so wasn't sure what they were.