This is a pair of hand carved obsidian stone bookends, made in Mexico, or perhaps Argentina or Peru, but most likely Mexico, circa 1940.
I think the bookends are pretty cool. There is a lot of labor involved in making the stone figures. There is a Native American face on each bookend, perhaps meant to be a chief or an Aztec warrior, don't really know, with headdresses and necklaces made of different polished stones, and applied to the obsidian. The figure on the left has the head of a predator bird, perhaps a hawk or eagle, above the forehead, with an elaborate alternating stone headdress. If you look closely, you will see that in addition the darker green is colored and carved to show veins in a leaf, so that the olive brown color of the underlying stone shows through the green. The alternating stones correspond to the bookend on the right. At the top is a round circle of small stones with a central stone inside. The necklace has smaller stones that are similar to the headdress, and some purple, green and brown polished stones that someone who collects stones will recognize.
The bookend on the left, at the top, there isn’t a stone that pops out, like the other bookend. I don’t know if a stone is missing or if this is how it is supposed to look. It appears normal to me, however do look at the photos carefully.
Each bookend is approximately 8 ¼” high and the base is approximately 1 ¾” by 2 ¼”.
The bookend on the right, on the upper right corner, it appears that the estate made a glued repair at one time, where the corner came off.
This is stone, not glass or porcelain, so if there are any other irregularities, I don’t know what they are.
The stone is solid black, with no traces of any other color, and this is why I think the stone is obsidian, versus onyx. The stone looks like solid black glass.