Any help appreciated on this necklace

[e-perfume]

Hi folks

I bought this piece at a garage sale many many years ago and I have just noticed that the clasp says 18KGT.  Would it be safe to assume that all the gold colour in the necklace is 18 Karat gold?

I have tried researching to try and understand how this necklace was made and the only thing I can find out is that the silver around the two black stones is called foiling?   Not sure what the colours are made of or how its made so if anyone can give me any info at all I would appreciate it.  

I will not be selling this necklace as I love it and wear it but I would really like to know more about it.  I have attached three pictures that I hope will help.

Thanks in advance

[christinesclassicjewelry]

The info I have seen on google about KGT markings is that it means karat gold tone. The mark seems like another way to confuse people into thinking things are gold. It could be plated, but it is almost definitely not solid gold. You can use a magnet to test it, if it sticks, it is not gold. If it doesn't, it is still probably not gold, but it is one simple way to know for sure that it isn't. 

The beads look like dichroic glass to me, and are very pretty!

Even though it is probably not gold, still enjoy it - it is a very pretty necklace!