Argentite (Acanthite) w/ Calcite (rare old classic - Phil Scalisi Coll.)

Item Description

Acanthite is RARE from the old copper mines and more modern iron mines in the Medenec area of the Czech portion of the historic Erzgebirge. This showy and rich piece probably dates to the early 1800s. It is said to be from the Hans Karabacek Collection, 1878 to 1963, a prominent Austrian mineral collector. Read about him at: https://mineralogicalrecord.com/biographies_labels/karabacekhans-j/. Much of his collection went to Harvard after his death, although no original label was provided when it was exchanged out of Harvard into the Scalisi Collection (his #269) several decades ago. The rich mound of pseudo-cubic, subhedral and anhedral acanthite plus the accenting calcite make for an attractive horizon on the sawed quartz-rich matrix. Argentite is the high-temperature form of Silver sulfide, only stable above 177 C. Below this temperature Argentite converts to Acanthite (MINDAT). A very rich and rare old example from the locality. Note the crystal style is unusual and it had been misidentified as sternbergite in the past. Valued at $1250-1500.