Stringy Moss Agate from Lake Bonneville Idaho is odd-looking stuff. Definitely a candidate for weird microscopic life, or perhaps something you'd find around a geothermal vent deep in the ocean.
This slab of Orbicular Ocean Jasper from Madagascar is a lovely subtle rock, so it may take a bit of time to get my eye in to appreciate the subtle colours and patterns. A couple of shots struck me as instantly interesting so they went straight up to redbubble.