50 HOLLAND: MICA DEPOSITS OF INDIA. 



and heaps of iron -slag in many places show that in the past a consider- 

 able industry existed ; the Kols still in a casual way smelt a certain 

 amount of iron in a bloomery, which is essentially similar to that 

 employed for the direct process by other out-caste tribes of India. 

 Much of the ore used is obtained by washing river-sand, and there are 

 cases recorded of the accidental production of tin from the ore so 

 obtained. In his geological notes on part of Northern Hazanbigh, 

 Mr. Mallet mentions an instance of this, and the writer has lately had 

 an opportunity of confirming the story by chemical examination of the 

 furnace-products obtained through Mr. Mervyn Smith from the iron- 

 smelters near Bendi. Although, on account of its greater specific gravity, 

 cassiterite concentrates by washing even in the presence of iron-ore, the 

 observations recorded above should warrant a careful watch for larger 

 deposits of the mineral. According to Mr. Mallet's account of the ore 

 discovered, and for a short while worked, near the Barikar river, eight 

 miles west of Giridih, the tin-stone occurred in lenticular bands in the 

 gneiss which, judging by the habits of cassiterite, were not improbably 

 granitic veins. Isolated grains of cassiterite are often found in 

 lepidolite near Pihra (24 38' 30" ; 85 51'), where its association also 

 with indicolite and other forms of tourmaline and fluor-spar is in 

 agreement with its occurrences in other parts of the world. 



To a small extent it may be found possible to utilize as bye- 

 products the phosphatic minerals occurring in the mica-bearing 

 pegmatites. Pale-green apatite has been found in several localities, 

 the most abundant being in the Lakamandwa mine near Koderma, 

 where the schists surrounding the pegmatite-vein are also impreg- 

 nated with phosphate of lime. Anexperiment was made by the writer 

 to test the abundance of apatite obtainable from the waste material 

 thrown out by the miners from the Lakamandwa mine. Three 

 boys were shown specimens of the mineral, and for a pay of 4^ 

 annas picked out, in 7 working hours, 100 lbs. of the mineral from the 

 fresh waste. A much larger quantity might have been obtained if the 

 boys had been practised previously in recognising the mineral, and still 

 more if the mud and soft mica films which coated the apatite had been 



( 40 ) 



