I hope this doesn’t sound like a lecture, just trying to help. Authentic, well only 1 person knows that, the person who made it. That’s always the bottom line with Native American Jewelry. Unless you watched someone make it, and buy from the craftsman. Few more tips, Native American jewelry was not often signed at All, Ever, until roughly 1970. Native American jewelry pre 1970 is a subject that fills books. When buying any tourquise, one must take a good look, and judue based on many factors. This is petit point. Very small pieces of gemstones, or plastic, enamels, etc, making up a entire work. Very easy to use fake block tourquise to do this. However, it’s also the best way to use small almost perfect blue gemstones of tourquise. Spend some time reading about fake or Block tourquise. This will help. Look for small irregularities in the blue, this speak of the real deal. Look at tourquise in nature,raw,and u will see why this type of jewelry is made, tourquise has a matrix of other things such as pyrite. It is found with copper. That said, this looks like a lovely piece of Native American Jewelry with a nice patina on the back. The pin and pendant clasp are common to legitimacy, I imagine you understand patinas, these can be faked. This is not generally the style of jewelry that is " fake ". Much fake non Native, “Native looking” Jewelery is simply American or Mexican , Chinese, inexpensive jewelry sold as real tourquise, its about making that 150$ from what is 10$ tourist, or costume jewelry. Often what’s called nickel silver, Tibetian Silver, ( both not silver ), its cheap jewelry that has block tourquise. Block tourquise is a must look up online for anyone who buys tourquise. If you see a 925, meaning .925 silver content, chances are thats the real deal, Sterling Silver. Most fake torquoise is not placed in real Silver. So, one must judge the piece as a whole based on all these factors, but most important…do u love it? If so, it’s for you. I own a bolo exactly like this, marked 350. at a San Francisco Jewelers, I paid 150., as I shop so often with them. I think it’s legit, hope this helps you or someone. Best, Bartleby.