1892.] NATURAL SCIENCES OF PHILADELPHIA. 179 



in crystals which for perfection are probably unequalled. One of 

 about the size of a pea is almost perfect on all sides, having the 

 prism and two domes. One crystal, nut perfect but showing five 

 planes, measured 2\ x4 inches, and others, showing all the prismatic 

 planes, H x 2 inches. 



The minerals described occurred in the largest quarry, situated 

 northeast of Frankford Creek and between Adams and Church 

 Streets, chiefly towards the northern end of the quarry. In the 

 gneiss at the extreme south end of this quarry was a bed of ortho- 

 clase in which was found the randite, usually as a very thin coating 

 on orthoclase, sometimes in groups of microscopic acicular crystals, 

 occasionally imbedded in calcite. 



Some of the orthoclase of this quarry has a pink tint, due, as 

 shown by the microscojDC, to minute crystals, probably of gothite. 

 Tourmaline occurred in poor crystals and also as a rock-like mass 

 coating the gneiss. Muscovite is found, but in poor specimens ; also 

 lepidomelane in large cleavable masses. Epidote and sphene, the 

 latter in minute but perfect crystals, were found rarely. 



In a small quarry, adjacent to the above, lying across Church 

 Street, was a small bed of calcite in the gneiss containing fine 

 crystals of epidote, some an inch or two long, terminated, and one, 

 measuring I x 2t inches, showing prism faces only, but those brilliant 

 and perfect. Crystallized hornblende was sometimes found but was 

 rare. Hyalite containing uranium was also found. 



Beside these the following were found in indifferent specimens : . 

 Iceland spar, chalcopyrite, bornite, malachite, chrysocoUa, apatite, 

 fluorite. 



On Frankford Creek, above this quarry, there is a granite con- 

 taining reddish orthoclase and greenish oligoclase. 



In a small quarry on Little Tacony Creek west of Frankford 

 Road apophyllite was found ; the first place at which it was dis- 

 covered in this vicinity. 



In its westward strike this Frankford gneiss is next met with near 

 Wayne Junction, Germantown. The railroad here crosses the 

 turnpike, or Germantown Road, and formerly there was a large 

 quarry in rock very like that of Frankford, except that near the 

 surface it was much decomposed. This was the locality of the 

 philadelphite which occurred as the mica in a schist, and also in 

 small veins in the rock. From the occurrence deeper in the quarry 

 of precisely similiar veins of hornblende and the fact that the hard 



