Black Bangle, Glass Or Stone

It's pitch black so I can tell if stone or glass.
What do you think?

 

Is it a drill hole far left side bottom photo?

 

No holes.

 

There is a black glass that is translucent when held up to a light, showing a dark color, purple maybe. Glass should 'clink' when you tap it on your teeth, like a drinking glass does.

 

It's opaque and stays black when held against light. Should only glass clink when tap on teeth? I'd think some stones would do that as well.

 

Black onyx I think it is!