Among foreign mineralogists and collectors, Libethenite Cu2(PO4)(OH) is probably the best known mineral from Slovakia. It was first described in 1823 by J. F. August Breithaupt, a leading mineralogist of the 19th century, a German professor at the Freiberg Mining Academy. He named it after the German name for the town of Ľubietová – Libethen. The importance of this mineral has also been underlined by the fact that the crystal is the central theme of the logo of the Mineralogical Society of Slovakia – today's successor to the world's second oldest mineralogical society, founded in 1811 in Banská Štiavnica.
Libethenite crystallizes in an orthorhombic crystal system and mostly forms short-prism or dipyramidal emerald green to green-black crystals. Crystals of up to 11 mm in size are mainly found with malachite and pseudomalachite in the oxidation zone of the deposit at Podlipa near Ľubietová, which is still the world's most significant deposit of this mineral. Other important locations include e.g. Portugal, England, Russia, Zambia, etc.
The stamp and maximum card (CM) bear the image of a typical dark-green Libethenite crystal from the Dolná Ladislav shaft in Ľubietová. On the first day cover (FDC), there is a typical sample of corroded quartz with Libethenite crystals from Ľubietová on the surcharge. On the postmark with the date of the first day of the stamp issue, there is the typical shape of the crystals of Libethenite from Ľubietová, which was originally published by the important Hungarian mineralogist and crystallographer, Gustáv Melczer, in 1904 (born in 1869 in Dobšiná). In the interstitial, there is a depiction of a flowing aggregate of malachite from Ľubietová, the Podlipa deposit. This mineral is the most abundant mineral in the oxidation zones of copper deposits and it may also be found in abundance in both deposits in Ľubietová.

Daniel Ozdín