Unlike the majority of such veins in the area, these are very narrow and lack a substantial muscovite-rich zone along the contact. They are composed of mostly equal parts massive topaz (pale honey-brown color) and white quartz. the veins are typically 1 to 2 dm wide. There are only very small (~1 cm) pockets.
January 25, 2010. View of the road cut about 3 to 4 m tall, with narrow subvertical topaz vein in center. This is one of several such veins in the long cut in Collinsville Gneiss, which appear to parallel a set of similarly-oriented joints.