10 strands, appears to be strung on string, VERY small & the end cones are marked sterling.
I usually guess by feeling it with my teeth. If it feels really smooth, it’s more plastic than mineral. If it’s gritty, that’s a good sign. This isn’t a very scientific method, but I figure if it works for pearls, it’ll work for turquoise too.
It is a beautiful necklace. We always have the same dilemma with this style of necklace. It would be my thought that this is not turquoise.