I have seen a few rocks in my day that are really beautiful. Here are four examples.
A close-up of sandstone with iron oxide cementing the grains in colorful patterns near Kanab, Utah.
A rhyolite porphyry with pink feldspar crystals and blue quartz crystals near Llano, TX.
A breccia in Mosaic Canyon in Death Valley National Park, CA
An intricately folded and banded iron formation with hematite (gray) and jasper (red) layers near Ishpeming, MI