590 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. XXVII. 



crystals may be due to incipient weathering. The colour is white. The tops 

 are perfectly flat. Often fine hexagonal columns are found lying on their sides. 

 (/) There are also barrel shaped crystals, probably having nine 

 sides, capped by three pentagonal faces meeting in a point at the top of the 

 colunm. The appearance of the column is very peculiar. It looks as if several 

 flat discs were piled up in a barrel shape without minute ^^ustment, so that 

 the sides are rough and uneven. Sometimes the columtris pinched in the 

 middle producing the effect of two barrels placed one above the other. The 

 colour is translucent white. 



(gr) There is lastly a form of calcite found in the lower trap which is very 

 rare indeed but which also occurs in the Nowroji HiU trap. The crystals have 

 the appearance of cubes but with slightly convex sides. The convexity is caused 

 by the meeting of very flat crystalline faces. This is weU seen in the crystals 

 which are bright, but in those with dull surfaces, as is generally the case, the 

 cause of the convexity seems rather puzzling. 



(h) Besides the above there are some obscure forms. 



III. Next is frequency, but much less in quantity is the occurrence of quartz. 

 It fiUs the lines of cleavage in the upper trap as thin veins of amorphous quartz. 

 So far no large crystals have been found either in the veins or in cavities in this 

 trap, which at present is being quarried to a very limited extent. In the lower 

 trap crystalline quartz is common and it occurs in weU formed transparent 

 crystals, very often cream coloured. It is generally associated with?- calcite and 

 zeolites. In the sedimentary beds quartz is found, though scantily, in a crys- 

 talline form filling the cracks in the beds. 



{a) The amorphous quartz of the trap veins is found in thin plates which 

 are rather difficult to detach from the rock. The mineral invariably crumbles 

 into powder on being detached. 



(6) The crystals from the lower trap and the sedimentary beds are extremely 

 interesting. They are of a fine transparency and peculiar lustre. Generally 

 a rhombic face is exposed and less frequently a pyramid formed by four rhombic 

 faces is seen protruding beyond the general mass of the mineral. It is rarely 

 that the crystals are found as two four-sided pyramids joined by a column 

 similarly facetted. A broken siirface shows a pearly lust)'e. A careful study 

 may perhaps show that this mineral is an apophylhte. It is occasionally 

 found in a weathered condition. In association with these crystals creamy 

 coloured quartz , crystalline and with fine strise on the sides, is occasionally 

 met with. 



(c) Then again the mineral is found in extremely fine six-sided needles 

 capped by a pyramid either at one or both ends. These needles are sometimes 

 found standing out in the cavities of the lower trap but more often are mixed 

 up with the mass of the rock. This is especially the case with the quartz 

 crystals found in the pecuUar ' boulders previously mentioned. Some of the 

 crystals have their tops fused and rugged while others have their pyramids cut 

 off in a plane which gives a pentagonal appearance to the face. They 

 are transparent and vary in colour from smoky to pure white. The general 

 look of the crystals is as if they have had been developed out of a fused mass. 



IV. ZeoHtes : (a) Intercalated with the shales there occurs a dark grey 

 ■zeolite. It forms extensive but thin films. Owing to its thinness it is extremely 

 iragile. It is not also firmly attached to the rock with the result that it easily 

 gets detached and broken. 



(6) In the cavities and cracks of the lower trap there is found a fine white 

 zeohte either by itself or in association with quartz and calcite. It occurs in 

 sheaves and has the appearance of a stilbite. Taken altogether the mineral 

 is rather common but it is not found in large lumps. 



V. Besides the minerals described above there is met with in the sedimentary 

 shales a waxy looking translucent mineral. It occurs in small, very thin 



