Bakelite-era plastic belt buckles and buttons that belonged to my great Aunt Myrta (1896-1980).
The bright colors and geometric shapes-within-shapes make me think of Robert Indiana's work.
Looking through the collection, I imagined her examining each piece the way I do, responding to the shapes, colors, sculptural qualities, the decorative details, perhaps thinking about which buckle or button might work with which fabric or dress pattern, because when she was young, either she or her mother made most of their clothes.
Japanese influence is everywhere in the design. Materials such as coral, jade, ivory and laquerware come to mind, as well as the colors seen in Japanese prints, like this one by Utamaro.
This diamond-in-oval motif reminded me of this curtain design from the book, "Japanese Detail: Architecture" . by Sadao Hibi.
There are triangular pyramids...
In the buttons above and below, the same motif takes on a couple of different spins.
This metal button (there's actually a few of them) was a wild card in the bunch-- nice architectural details in the center surrounded by hearts. At first glance it struck me as being different than the other pieces, in both the material and decorative motif, but if you think of the design as a geometric shape within a circle, it's consistent with the others.
This is Aunt Myrta with her Franklin car, in a photo taken here in central Texas around 1915. Love the outfit, and particularly the way she's slung the big belt loosely over her lightweight (probably cottton?) dress - very Southern Girl-Goes-West (and the focus on the belt just might explain all the buckles she saved...)