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Jasper from Kosákov

Material name: Jasper
Synonyms: N/A
Material (geologic): Jasper

Detail of jasper from Kozákov
Foto: Matthias Rummer, 2001

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General characteristics

Geographical setting: Kozákov is a quite prominent hill, in the area of the Český ráy on the Northeastern fringe of the Bohemian Basin, approx. 10 km east of Turnov. It rises approx. 450 above the surrounding countryside, reaching 744 metres asl and is the biggest hill in the Krjkonose Foothills. The basic mass consists of Paleozoic melaphyres but the top and the northern and eastern slopes are covered with tertiary basalts and other effusive volcanic sediments.
Covering an area of approx. 160 ha, it was decreed a preserved territory in 1985 in order to protect the geological and geomorphological phenomena. The primary exposure is located on the southern flank of the hill in an abandoned quarry.
Material and colour: The material exposed in the quarry is quite varied, with melaphyr and other rocks of less archaeological interest. The material presumably used for knapped stone tools is a not too fine siliceous mass, known in the literature a "Jasper", of reddish and/or greenish colour. As the disused quarry where the sample was taken is a favourite with rockhounds, obtaining first-class material is getting quite difficult. The jasper in our sample is only of very limited use for the production of tools, but large lumps of very amorph and homogeneous material, excellently suitable for knapping are known from the area.
Other information: No prehistoric extraction of the material is known at the moment, but as it is one of the very few sources of silicious knappable material in the wider region, prehistoric use is quite probable. During the later stages of prehistory, it is a well known source for semi-precious stones.
Knapping notes: The samples available to us at the moment are not really suited for knapping, but the somewhat crystalline matrix makes it probably quite difficult to knap. Some slight taps with a geological hammer to break up the original blocks to obtain good specimens for the photos brought out quite a lot of internal fissures. The siliceous mass between the cracks, however has a good conchoidal fracture but it needs quite some force to detach the flakes.
Archaeological description: Evidence for prehistoric use of the jasper from Kozákov is very slight. Basically, the only reference is in Schenk 1981, where its use in the Neolithic is mentioned. Even so, it will have been a material of local importance only, but as it is one of the few sites with knappable stone in Bohemia, we still list it as a source.
Thanks and acknowledgements: We would like to thank Ivan Turnovec, formerly of the Czech Geological Survey, now a free-lance editor and publisher, for helping us with the geological background of the region.


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Kozákov

Locality: Kozákov hill, Český ráy, Bohemia, Czech republic
Synonyms: N/A
Geographical description: The Jasper is exposed in an abandoned quarry on the south slope of the hill, at a height of approx. 550-600 metres asl, directly above the small village of Kozákov
Geographical co-ordinates: Lat. 50 35' 22" N
Long. 015 15' 40" E
(Mapdatum WGS 84)

Co-ordinate precision: The co-ordinates given were taken with a handheld GPS receiver in the quarry, and should be accurate enough to find your way to the exposure.
Other topographical information: Finding your way in the region is not very easy, as the very narrow twist and turn among the hills. Get a good map in one of the larger towns, we recommend map 19 "Český ráj" in the 1 : 50 000 series of the Czech Tourist Club.
After finding your way to the village of Kozákov, you can leave your car at the western end of the settlement, where a path leads directly towards the quarry (Czech: "Lom"). In the surrounding woods, numerous pits and hollows indicate older mining activities.
Additional information: Kozákov hill seen from the south
Foto: Andreas Kinne, 2000
  In the picture above, you are looking from the south towards Kozákov hill. The quarry where we did our sampling is hardly visible between the trees, slightly to the right of the centre.
Visitors information: On the summit of the hill, you have a great view of surrounding countryside, and can be reached over several marked trails. On the slopes there are two pseudokarst caves called Babí and Kudrnácova pec. The next possibility for a bite and a drink is at Podloktuši, three kilometers to the west of the village of Kozákov. Here you can get traditional Bohemian food at traditional prices and there are possibilities to spend the night. The next camp site is in Sedmihorky, at the foot of the rock formations of Hrubá Skálá.
Sampling information: View of the disused quarry
Foto: Andreas Kinne, 2000
  The sample we bring you was taken from the disused quarry you see above. The site is well known and quite popular with rock hounds and others interested in stones. To enter the quarry, you are supposed to pay a very small fee (in may 2000 approx. 0,30 €) at the building near the road. Here you can visit a small exposition on the semi-precious stones from Kozákov and, if you feel like it, have your own finds polished. Officially, the site is open from 10 to 17 H, but the quarry is accessible anytime.
For a full-blown picture of this sample, click here (73 KBytes). Flake of jasper from Kosákov
Foto: Matthias Rummer, 2001
Block of white siliceous material
Foto: Matthias Rummer, 2001

 
For a full-blown version of this picture, click here (67 KBytes).
For a full-blown picture of this sample, click here (69 KBytes). Sample with veins of chalcedony
Foto: Matthias Rummer, 2001
Sample description: N/A

 

Last modified on:
May 16, 2001
Contents primarily by:
Andreas Kinne/Rengert Elburg
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