A nice hand specimen... John Buchanan February 18, 2022 of a trachyte porphyry from the La Sal Mountain laccolith (Eocene) showing euhedral orthoclase phenocrysts 1-4 cm long. The dark phenocryst in the center of the image shows clear zoning. The groundmass consists of orthoclase with minor plagioclase, biotite, hornblende and augite.