QUARTZ (JASPER) 501 



A large amount of brown jasper associated with red and yellow jasper is found at 

 Sioux Falls, in Dakota, North America. About 30,000 dollars' worth is cut every year in 

 large works on the spot, the material being used specially for the ornamentation of 

 buildings. It is known in America as " Sioux Falls jasper," and occurs in inexhaustible 

 beds, which are excavated in quarries. 



Yellow jasper is much employed in Florentine mosaics, but is otherwise unim- 

 portant. It has brownish and white streaks on an ochre-yellow ground, and is obtained 

 from the island of Sicily, from Dauphine, and elsewhere. 



Green jasper is found principally in the Urals, where also it is worked. It 

 occurs, among other places, at Orsk on the Ural river above Orenburg, where it 

 forms a thick bed in gneiss. This bed has furnished blocks of sufficient size to be 

 worked into vases and other large objects, all the cutting being done in the great 

 works at Ekaterinburg. The colour is dark leek-green, and the stone is therefore known 

 by the name of plasma, a variety of chalcedony, which it resembles in appearance. Green 

 jasper is much esteemed in China, and is one of the stones to which the term " yu" 

 is applied. 



Blue jasper is always rather dull in colour, frequently showing a lavender or grey 

 tinge, and is seldom used. We may mention here the so-called porcehbi-jaspir, \\hich is 

 not really jasper at all, but is clay baked and hardened by the burning of lignite (brown 

 coal). It is usually lavender-blue in colour, but may be tile-red or yellow ; it is widely 

 distributed, especially in northern Bohemia, and a specimen is now and again used as an 

 ornamental stone. 



Riband-jasper has differently coloured riband-like bands which alternate regularly 

 with each other. It is very impure and can scarcely be properly regarded as jasper, its 

 chemical composition approximating more closely to that of felspar than to that of quartz. 

 It closely resembles typical jasper in appearance, and, indeed, differs from it only in its 

 fusibility before the blowpipe, and in the large amount of foreign matter it contains. 

 Riband-jasper, in which the contrast between bands of colour is not sufficiently marked to 

 be effective, is common enough ; it is found in beds at Lautenthnl, in the Harz, at 

 Gnandstein, near Ivohren, in Saxony, and other places. The Siberian riband-jasper, on the 

 other hand, in which dark blood-red and leek-green bands alternate with great regularity, 

 is most beautiful. It is said to occur near Verchne-Uralsk, at the junction of the Uralsda 

 with the Ural river, but only in small loose pieces, so that only comparatively small 

 articles can be made of it : larger objects, however, are often veneered with thin plates of 

 riband-jasper. Jasper of exactly the same description is said to occur at Okhotsk, in 

 Eastern Siberia, and good specimens are stated to be found also in Chutia Nagpur, in 

 India. Fine riband-jasper with yellow and red, alternating with white stripes, is found in 

 large amount at Collyer, in Trego County, Kansas. It is an excellent material for cameos, 

 for which purpose onyx, or riband-agate, is also very well suited, owing to its regular 

 banded structure. 



TTie stones which are intermediate in character between jasper and chalcedony, and 

 which may be termed agate-jasper or jasp-agate, usually show opaque, dark coloured 

 portions intermixed in various ways with translucent, lighter coloured portions. Such 

 stones are the once much talked of "jaspe fleure" of jewellers, and they were at one 

 time worked like jasper. The material occurred in large amount principally in Sicily, 

 where a hxmdred varieties, distinguished by differences in colour and markings, were 

 recognised. A fine agate-jasper occurs at various places in Texas, and is often called 

 in America " Texas agate." In some of these stones the translucent agate predominates. 



