I am not sure how this one came about, but I liked it enough to print it. I believe it was from realizing I forgot the lens cap on my Fujica GL690 and pulled it off before the AE lens had finished it's long, dark shutter cycle, which means it may be repeatable if I want to try for some more abstracts.
Thanks for the comments. I found another, very dense negative was a similar, lighter pattern exposed in a shot of a tree. I have had a hard time remembering a rangefinder camera has a clear view whether the cap is on the lens or not.