Hello and welcome to the forum, @Kenda. Your mother’s belt is a beauty.
It is generally agreed upon that there are three “phases” of concho belts.
- First Phase belts were crafted shortly after the Navajo’s return from Bosque Redondo in 1868. Roughly 1870 ~ 1920, depending on who you’re asking. These belts are identified by the concho’s diamond shape cutouts that the leather is laced through, and their small, harness type buckles. True First Phase belts are comprised of both round and oval conchos, with the round being thought of as being made earlier. Here is a fine example.
Navajo, ca. 1870
- Second Phase belts, crafted from the 1880’s through the early 1900’s, saw the introduction and implementation of soldering (most generally) copper straps on the back of the closed center conchos to secure them to the leather, as well as repoussé design elements, and larger, more ornate buckles. These belts are much more elaborate in their embellishment and overall execution than First Phase belts.
Navajo, ca. 1905
- Third Phase belts are identified by the ‘butterfly” spacers that separate the conchos, as well as the introduction of turquoise. These were crafted from the early 1900’s through the 30’s and showcase the refinement of the form.
Navajo, ca. 1930’s
Please know that nothing I’ve mentioned above is by any means set in stone. There are many museum collected examples with provenance that cross over the prescribed timelines, and there are countless other considerations, but, with any luck, perhaps some of this will provide you with a rough idea.
Your mother’s belt is what would be classified as a First Phase revival; meaning it is crafted in the style of the original First Phase belts, but at a much later date. The revival of the older belts has been commonly practiced from the Second Phase to current day. It looks like it could have been crafted in the 60’s or 70’s, when Native American jewelry was really starting to boom, and that is shored up by the decades you believe she acquired it within.
Here is a thread containing a somewhat similar belt as well as some great info.
If you’re really wanting to learn, check out @TAH’s Belt Buckles & Concho Belts thread.
Concerning a valuation, personally, I’m not comfortable providing one. There exist numerous examples of similar belts that have sold that could provide you some insight. As far as selling it, there’s always eBay, with its steep fees, or you could consider consigning it to a gallery in the Southwest.
Thank you for sharing!