How can you identify genuine turquoise?

Genuine turquoise has a natural, irregular matrix with inclusions, a somewhat porous surface too, and a Mohs hardness of 5 to 6, so it ends up clearly tougher than most plastic or resin imitations.

One common simulant you will see in the market is dyed howlite, which readily shows a pale interior when scratched or after acetone is applied. Natural turquoise also carries shifts in colour and matrix patterning that look fully organic, not that uniform, printed look you get from synthetic blocks. Some professional gemmologists go a step further with specific gravity checks to tell it apart from compressed or stabilised turquoise composites.