This is a belated reply but the topic is perhaps more relevant than ever because many supposedly "leather" items that I'm coming across are anything but.
My impression of Stone & Co, which is a spinoff of Stone Mountain, is that the wallets are entirely synthetic, even though the boxes as of this date are labeled "leather" on the packaging. Many of the wallets and clutches I've seen do not even contain a label to indicate materials. It used to be that if you purchased a genuine leather article it would be clearly stamped in the leather. In situations where the advertising doesn't follow through to the stitched-in or stamped on label, in all likelihood the item is NOT constructed of genuine leather.
A few years ago I bought a pair of athletic shoes that had been offered in a particular style and constructed of "glove soft leather" for years. The hang tags on the outside of the shoes indicated that they were leather but underneath the tongue the material was described as "manmade upper". In going through the boxes that corresponded with the display, I did not find any genuine leather shoes. Upon contacting the manufacturer, which was simultaneously advertising the shoe as "leather" on their website, I was told that they are synthetic leather. Well, synthetic is still manmade and so the use of the term "leather" to refer to materials that are manmade constitutes false advertising, in my view! (At the time, all the websites that sold this shoe were following the manufacturer's lead by misrepresenting the materials as "genuine leather".)
I looked in some of the recent bags by Stone & Co in a well-known department store and found that they do not not disclose the presence of any synthetic materials, whereas Tignannello — the last time I purchased the brand — clearly indicated that the product is a mix. So yes, in answer to your question, I think the materials are at best a mix, very similar to the way Tignanello uses vinyl for all the handles and attachment points. My nose, unfortunately, detected nothing but freshly manufactured plastic, despite the "leather" tag sewn into the bags.
In my view, there is a widespread issue with label misrepresentation on shoes and accessories. Many continue to advertise leather on packaging when they have little if any actual leather. This is important for several reasons: 1) Petroleum-based products — plastics — contain endocrine disrupters and the over-use of plastics in our environment may be contributing to rising rates of cancer, among other health issues. (The health effects of plastics are beginning to go mainstream, having even made an episode of the Dr. Oz show recently.); and 2) leathergoods are more likely to be repaired if they break, to last longer, to break in (conform to the foot when used in footwear) and to be given a "second life" in a thrift store or on Ebay as opposed to landing in a landfill; 3) plastic handbags are not "biodegradable".
I once worked in a leathergoods repair and sales shop, and while the feel of leather can be replicated the smell never can be. Let your nose be your guide, not the label, not the advertising.