Very interesting pattern on this rock

Found in a creekbed in Montana and posted in the whatsthisrock subreddit, where there is a detailed explanation of how such a complex pattern could evolve.

Posted for the delightful image, which as an old rockhound I find fascinating.  The explanation about how cracks can form in quartz because of differential strain between hard quartz and soft(er) surroundings is well over my head, and I will never remember that this is "the very first phase of boudinage," but it is a cool image and belongs in the blog.