česky english deutsch <<< >>>

Žula v Geoparku

Smolné Pece

Characteristic rocks associated with granite intrusions are pegmatites. They are coarse-grained magmatic rocks, which crystallized from residual fluids in fissures in the proper granite body as well as in its wide surroundings.

The Pegmatite pit

Granite pegmatites are source of valuable raw materials, mainly feldspars for ceramic industry and micas for electrical industry. Feldspar was an important raw material for porcelain factories, and in surroundings of Karlovy Vary it was mined in the past from small bodies of miarolite pegmatites. One of these occurrences is at the forested hill Hamerský vrch south of the village Smolné Pece at Nejdek. Here pegmatite penetrated into biotite granite of the Older Intrusive Complex (“gebirgsgranite”). It consists of a fine-grained (aplitic) contact zone and a central block zone with large segregations of grey quartz and pink potassium feldspar. It was mined by a small quarry, in the direction following vein down to underground stope, which bottom is now submerged in water along the whole year. Lower on the slope overgrown dumps are preserved. There some interesting minerals can be found.

Schorl

Schorl in Quartz

Schorl, a mineral of the tourmaline group, is noticeable by its black prismatic to acicular crystals. The longitude of the schorl aggregates reach up to several decimetres. Rosa quartz is massive, with variable colour intensity. On the light often becomes pale.

Muscovite

Muscovite is very characteristic mineral on the locality; it forms up to several centimetres large leafy crystals and its intergrowths with pearly lustre. Ilmenite occurs in irregular shaped flat crystal up to several centimetres wide, usually in feldspar. Cordierite (or its ferrous analogue sekaninaite) forms unsightly green-grey grains with perfect cleavage, often strongly weathered.

The feldspar mine at Smolné Pece is the only outcrop of granite pegmatite in western Krušné hory Mts. and thanks its regional exceptionality it would deserve a protection.

GPS position

N 50° 17.297', E 12° 45.972'
[GPX]

[MAPY.CZ]