Are these glass or garnet or???

I'm not sure what these are made of. Cold to the touch. A bit on the heavy side. Depending on the light, appear as a deep red or have a slight violet hue. I took several close-up photographs under different lighting.

 

Are there air bubbles inside, looks a bit like it from the pics?

 

I'm not sure if those are bubbles or imperfections. I did not see anything until I saw the photographs. I just magnified the photo that is directly on the light. I still can't tell but, that could just be my old eyes.

 

Looks like garnet, but only testing will prove it.

Looks like this necklace:
https://www.healingcrystals.com/Necklaces_-_Garnet_Tumbled_Chips_Necklace__India_.html

 

Garnet chips, I've seen a fair few.

 

Same here. No question. I've seen tons of them.

 

Thanks everyone. I'm finally tackling the armoire and closet that is full of costume jewelry that I inherited several years ago and this piece was in there. I did find some 14K and 18K gold rings and necklaces so, I thought I would double check before I decide which pile it goes in. I didn't realize garnet chips were so inexpensive. That was a bit of surprise. Thanks again for the help.

 

Another one here who has seen many of them. Always this nice depth of colour.

They are from India, and they aren't cut, which makes a difference too.

 

And again, the story of the Thames garnets.

https://www.beachcombingmagazine.com/blogs/news/mudlarking-the-mystery-of-the-thames-garnets