This fine and rare old-time specimen features rare species Thomsenolite from the type locality of Ivigtut in Greenland. This is a noteworthy and attractive specimen of this species. Thomsenolite is a hydrated sodium calcium aluminum fluoride and such good items are rarely seen. Several areas on the specimen are festooned with well-formed, quadrangular, transparent to translucent, colourless crystals of Thomsenolite in clusters and in sub-parallel growths composed of prismatic, monoclinic crystals. The crystals are lightly to moderately highlighted by brownish iron oxides. This fine piece was probably found during the mine was under construction in the late 19th Century to early 20th Century. Thomsenolite is named in honor of Hans Peter Jorgen Julius Thomsen who lived from 1826-1909, and was a chemistry professor at the University of Copenhagen, Denmark, and is attributed to being the founder of the Greenland cryolite/aluminum industry. To make good pictures was nearly impossible and so, this specimen is way better in kind.