A very well documented and fine Colorado classic piece, this comes with 5 old labels, one of which notes: Collected in 1946 by C.G. Coil. Clarence Coil was a significant figure in Colorado Mineralogy. Well formed, terminated crystals are on several sides and in one large vug. This was in many collections over the years, including Elberto Tealdi (Milan, Italy) and Richard Kosnar. The esthetics and satiny luster in person show why it was included in these fine collections.