Vintage Native American shop Sterling Silver & Turquoise Pendant Necklace

Product Name: Vintage Native American shop Sterling Silver & Turquoise Pendant Necklace
Breathtaking turquoise stone set in a classic Native American sterling silver setting (18" solid sterling chain included). This is a rare, large authentic turquoise cabachon and the pendant itself is just over 1 1/2". I purchased this from a vintage jeweler in Arizona and was told it is Navajo, shop although the mark on the back looks more Zuni to me. It looks like either a JR or TR? The piece has some wear and patina from age. It has been polished a bit. Please see pics and thanks for looking. Ships same or next day. :) Would make a wonderful gift for yourself or a loved one. This piece is highly collectible! (Black box not included).