High lustrous enargite crystals are lining small vugs in the rock. A classic from a very rare and old locality: "Formosa" is the historic name of modern Taiwan island. "Taihoku" (formerly Taipeh-fu) was the name of modern Taipei as a colony of Imperial Japan between 1985 and the end of WW II. The city was administered under Taihoku Prefecture, the name "Paihoku" on the label was a transcription error and is corrected on the Franz label. "Kinsoseki" was a gold mine working in the early 1900's:
"According to the monthly report for February of the Yokohama Chamber of Commerce, the value of the gold Gold Froduction. produced in Formosa during 1904, amounted to 1,800,000 yen against 1,000,000 yen, the record for 1901. This shows the great progress the gold mining industry in that island has made during the past few years. The principal mines in the island, now being worked, are Shozuiho, Kinsoseki and Botanko, the annual production of each mine being valued at 500,000 or 600,000 yen. At Taito, Giran, Keelung, and some other places there are several mines now under trial boring, and in addition applications for working 15 other gold fields have recently been received by the authorities. The mountainous districts running, through the middle of the island are believed to contain rich gold deposits, but investigations have not yet been made in this connection."
(Board of trade journal, Great Britain Board of Trade 1905)

Comes with old Alex Franz label and a second one without dealer's name which is very likely from Krantz.. A super-rare historic specimen!