Hello, amethyst necklaces are generally not very expensive. You can have a look at an ordinary jewelry store. At least crystal or glass won't lie to you.

However, amethyst on the market now is generally not natural. If it is natural amethyst, it is still valuable if the purple is rich and clean. You can also consider it online. Generally speaking, there are many amethysts imitated by glass on the market, and of course the price is cheaper.