THE FELSPAR GROUP (LABRADORITE) 435 



supposed granite is in reality a coarse-grained gneiss, that is to say, a member of the 

 crystalline schists. It is stated by Mr. G. F. Kunz that labradorite has not been 

 systematically sought for in this region for over a hundred years. 



Hitherto we have considered only the characters of labradorite from the coast of 

 Labrador. The mineral has a very wide distribution as the constituent of many different 

 kinds of rocks, but in by far the greater number of cases the coloured metallic sheen is 

 absent, and the mineral appears of a dull grey or whibe, not in the least suitable for 

 decorative purposes. Nevertheless, chatoyant labradorite has from time to time been found 

 at other localities, sometimes in such abundance and fine quality as to appreciably lower the 

 price usually asked for good stones. At other places the rock containing the labradorite is 

 worked and used for the decoration of buildings or even as a building stone. 



In 1781, soon after the first discovery of chatoyant labradorite in Labrador, specimens 

 of similar character were discovered in Russia ; and this country has proved to be 

 specially rich in this mineral. It was found first in the form of boulders at Peterhof near 

 St. Petersburg. These boulders usually reflect a blue colour, but their play of colour is not 

 equal to that of specimens from Labrador. Boulders of uncommonly large size, measuring 

 more than 4 feet by 2, were found on the banks of the Paulovka. Numbers of labradorite 

 boulders occur also at Miolo in Finland. The mineral was first discovered in Finland in 

 the twenties of the nineteenth century during the recommencement of work at a very old 

 iron mine at Ojamo, in the parish of Lojo, in the neighbourhood of Abo. It differs 

 somewhat from that found in Labrador, being very markedly translucent and almost 

 colourless instead of grey. Moreover, there are more colour reflections, and these are 

 sometimes arranged with more or less regularity ; for example, there may be concentric 

 chatoyant zones around a dark nucleus, the zones differing in colour, but each being 

 uniformly coloured over the whole of its area. 



The most important occurrence of chatoyant labradorite in Russia, or probably in any 

 country, is, however, in Volhynia and the country extending to the neighbourhood of Kiev. 

 Together with other minerals, especially diallage, it forms a rock known to petrologists as 

 gabbro. In places where this rock is very coarse-grained, single individuals of labradorite 

 reach a length of 5 inches, but in other places they measure no more than a few lines. The 

 colour of the mineral is variable, it may be dark grey or green, and the same fragment 

 sometimes displays several shades between pale and dark green. There is a very fine play 

 of colour over the face on which this phenomenon is usually observed : green, blue, yellow, 

 and red are all to be seen, but the two first predominate ; the yellow usually occurs between 

 stripes of green. 



This gabbro with chatoyant labradorite is one of the featin-es of the great south 

 Russian granitic area. It is not found in loose pebbles or boulders, but forms a great part 

 of the solid rock of this region and is excavated in quarries at various spots. It is worked, 

 for example, on the banks of the Bystrievka stream, near Kamennoi Brod in the district 

 of Radomysl, and it is this locality which furnished the material for the coloured columns 

 which ornament the Church of the Saviour at Moscow. Later on discoveries were made 

 west of Kamennoi Brod, at Goroshki, and at many other points in the district of Zitomir, 

 and now the rock has been traced into Government Kherson, where it was discovered in 

 1867 at Novo-Pavlovsk. 



Very fine labradorite with a uniform blue sheen has recently come into the market 

 •ostensibly from Brisbane in Queensland. 



The mineral is widely distributed throughout the United States of North America, 

 and is found in great abundance in Lewis and Essex Counties in the State of New York, 



