Topaz pseudomorphs (Pyknite) after potassium feldspar – 
Römerschacht, Altenberg Tin Mine, Sächsisches Erzgebirge, Germany
 
Honey-yellow Pyknite pseudomorphs after Potassium feldspar, as up to 10 x 3.8 cm-sized groups of "Stengeltopas" (columnar Topaz) in a groundmass of Quartz and flaky black Zinnwaldite mica, surrounding a „core“ of fine-grained Greisen rock with purplish-grey Fluorite. An excellent and highly representative cabinet specimen from the world-famous "Stockscheider" pegmatite cap of the Altenberg tin ore deposit! Historic find in 1968, from the exchange fund of the Freiberg School of Mines in Saxony