Quartz Var Smoky on Feldspar

A pretty cluster of deep Smoky Quartz crystals to 16 mm, nestled in a coarse Feldspar and Quartz granite matrix from the Mourne Mountains in County Down, Ireland.  Miarolitic cavities occur at several locations throughout the Mourne Mountains where a limited suite of well crystallised pegmatite minerals may occasionally be found.  The Quartz crystals are so smoky they appear opaque, and also exhibit some interesting, stepped growth structures on their terminations. Two of the termination faces are damaged, seemingly from contact damage during growth.  Although there is no accompanying old label or documentation, it is known this specimen is ex-the Philadelphia Academy of Natural Science and was originally part of the Samuel Ashmead Collection which later became a part of the core of the Philadelphia Collection.