This is a vintage geological illustration depicting granite veins within mica slate. The background is a pale yellow, representing the mica slate, with numerous thin, reddish-brown lines running diagonally across it, suggesting the layered structure of the slate. Overlaid on this background are several dark blue, irregular veins of granite. These veins branch and intersect, creating a network of darker lines that stand out against the lighter background. The veins are not uniform in width, and some appear thicker and more prominent than others. The illustration is framed by a decorative gold border. At the bottom, there is text in a dark font that reads "Granite Veins in Mica Slate. 20. Williamsburg, Mass.". The style of the illustration is reminiscent of early geological surveys and diagrams, with a focus on clear representation of geological features.