Featured Chinese Red Coral Necklace?

Hi!..this is a recent purchase via a Antique store....I purchased it because it looks like coral and it has the silver looking pendant with a scrolling vine type design on it.....at first I thought the metal might be silver, but there are no marks....I have no experience with coral...so I have no idea if this is actually coral or imitation....there is a vintage "S" hook clasp that looks a bit aged... if someone knows if this is coral or another type of stone...please feel free to share your thoughts......

 

The hook looks silver, but the red stuff doesn't resemble any coral I've ever seen.

 

I’ve had one with those findings and the sliding centrepiece and it was silver. Sometimes there is a mark is on those S clasps.

 

Wouldn't surprise me. The blow-up of the back of the slide shows a texture that confirms the "stone" is 100% glass.

 

There's all different types and shades of genuine red coral beads. The S-hook clasp will give an idea of the age. I read that they were popular in the 50s and 60s.

 

Identifying coral isn’t only about the color, texture is the main clue from pics. These ones are undoubtedly glass
Those S clasps are still made and used in Asia and India...

 

Please can you educate me? How can you tell tell the difference?