@RTone has given you some great information.
Natural vs stabilized will not change it’s ability to scratch. Stabilizing is mainly used so that material too brittle to use for jewelry can be used, and also watch out for composite turqoise, I am not sure about it’s hardness. Also, it is extremely hard to tell what is natural vs stabilized.
The formation of turquoise does not happen under pressure like say diamonds, it will never have a hard structure compared to some other gemstones. But it will get less wear around your neck vs your wrist or hand which tend to bump jewelry around. If you are worried about its durability but like blue there are many blue gemstones you could look at.
And finally
I apologize for my ramblings.