Pyroxenes. 13 



is to be found in the " dump." As the tunnels and drifts were run, 

 the wall-rock encountered was thrown in one place while the " un- 

 dressed ore " was carried to the surface and sorted. Lying as these 

 sorted lumps have lain for so many years exposed to the weather, one 

 would not expect to find minerals in a fresh condition, but the 

 locality is more interesting on account of other things than the intrin- 

 sic value of the minerals. Yet it is of no rare occurrence to break a 

 large mass of calcite and to find enclosed, perfectly fresh and unde- 

 composed crystals of pyroxene. 



The following is a list of the minerals found by me in this place : 

 Pyroxene, scapolite, quartz, graphite, apatite, sphene, calcite. 



The pyroxenes found here are peculiar on account of their size, the 

 inclusions which they carry and their external appearance. There 

 are at present, in the Museum, two of the largest ever found in the 

 State and probably in the world. The largest of the two measures 

 thirty-six inches in circumference and eighteen in length. The sec- 

 ond one is about eighteen inches in circumference by twelve in height. 

 Both crystals have their prism planes perfectly developed, the prism 

 planes I and i-i (Dana) being both present and about equally devel- 

 oped. Basal planes in both cases are lacking, appearances favoring 

 the idea that each is a fragment broken from larger crystals in blast- 

 ing or in dressing the ore. They are badly decomposed, though 

 as yet quite firm. The crystals are coarsely lamellar, parallel to O, 

 the lamellse varying in thickness from two to five mm. In external 

 appearance they are very rough, though the indentations are not deep. 

 These indentations are more like long, rather deep and interrupted strise. 

 It is rarely that the calcite causes a real indentation, though when 

 in contact with quartz the pyroxene is always moulded around it, 

 never penetrating it. In the fresher crystals which are broken from 

 the calcite the latter mineral is found closely fitting into the striations, 

 and has a peculiarly fine, granular, crystalline structure. The prism 

 angles of all crystals are quite sharp, but when the crystals are termi- 

 nated by pyramidal faces the interfacial angles are invariably rounded. 

 In the body of the crystals, especially the larger ones, are enclosed 

 rounded globules of well crystallized calcite and quartz. These 

 masses vary in size from inclusions of microscopic dimensions to that 

 of a walnut. Under these circumstances the calcite can be in no way 

 distinguished from that outside the crystals. Graphite is a very 

 common inclusion. Thin lamellae of graphite occur within the body 

 of the pyroxene and also gashing the exterior of the crystals. Large 



