One of the rockhounding pages I follow on Facebook posted this image of some dyed Indonesian jasper. I feel that it could easily be mistaken for turquoise or chrysocholla. Jasper is not a rare or expensive material, and like howlite or magnesite, it can be dyed an array of colors to imitate other stones.
This material is known by many names, like “Sea Sediment” Jasper, or “Aqua Terra” Jasper. At gem and bead shows, I have found that jasper like this was mostly used to make beads. When I saw the jasper cabbed up in these shapes, it would be easy to fool an inexperienced buyer into thinking that this is turquoise.
Lots of studying, IMO. But I feel like the matrix is the key when looking at turquoise. Turquoise that is uniform in color with no matrix at all can be a red flag. With the jasper, the matrix isn’t quite right. It’s too wild, and the “wild” matrix pattern covers the entire piece of turquoise. Which is very unusual for turquoise.