First Day Cover
首日封
Sobrescrito de 1.º Dia
SlovakiaSlovak Minerals – Sceptre Quartz from Šobov
Date of Issue : 11 October 2013
Quartz (SiO2) is one of the most common minerals in nature forming hexagonal columnar crystals finished with planes of trapezohedron or dipyramid.
A druse of crystals of ore minerals (sphalerite, chalcopyrite, galena) with quartz and calcite from Banská Štiavnica is depicted on FDC. And a crystalline structure of euchroite – secondary arsenate of copper from Ľubietová, which is one of 19 Slovak minerals first found and noted down in Slovakia, represents a motif of the FDC cancellation.
No comments:
Post a Comment