(Maya tuber glyph?)
Herringbone couches the top ribbon, and interlaced chevron stitch the bottom, which was basically not worth the effort to do in one color because it looks very much like herringbone. The spiral is a leftover bit of DMC Cébélia No. 20 I found on my table and plied. The weird glyph shape is more of the same, but two strands knotted together. I knotted knots together towards the bottom to make extra big knots, where the couching switches from buttonhole to fly stitch. (I think I'm a little bored with flat photography; yay macro.)
Astronomical aside - Venus transit observation today! Despite the recent eclipse viewing, I was not prepared for solar photography, so once again I just drew a picture in my little sketchpad. Labeling it was important, because the sketch looks like a circle with a dot on it.