Strontianite

Water-clear transparent Strontianite crystals line the vuggy surface of a porcelaneous milky-white Quartz matrix.  From the Clausthal-Zellerfeld district of the Harz Mountains in Lower Saxony, Germany, the Strontianite crystals are developed to around 5 mm and their habit is of the more flattened, spear-shaped form.
Ex. the Mineral Collection of Archduke Stephan Franz Viktor of Hungary (1817 to 1867), with a historic Archduke (Erzherzog) Stephan label incorporating his coat of arms.  This large label measures 9.9 x 8.1 cm and is complete (untrimmed) and is numbered 91/3.  A small label bearing this same number is glued beneath the specimen and a Carl Rumpff label, dated 1889, is attached to one side.