174 PROCEEDINGS OP THE ACADEMY OF [1893. 



NOTES ON SOME MINERALS AND ROCKS. 

 BY E. GOLDSMITH. 



Pimelite. The material was found by Mr. Theo. D. Rand on his 

 property at Radnor, Delaware Co., Penna., at a moderate depth. It 

 is soft and very finely micaceous, having an apple green color and is 

 greasy to the feel. Specific gravity was found with the Thoulet 

 solution to be 2*596. 



Beneath the microscope it shows irregular outlines. Dichroism 

 none. Interference colors brilliant. A cleavage is noticed in a direc- 

 tion apparently at right angles to the plates which give an inclined 

 extinction on rotating the object. The mineral is therefore defined 

 as crystallized and may belong to the monoclinic system. 



It is not fusible. With carbonate of soda on charcoal it affords a 

 black mass containing nickel. With the fluxes it shows silica, nickel 

 and irou. Hydrochloric acid decomposes it on boiling, leaving 

 some mixed sand ; after repeated boiling with the acid the insoluble 

 portion was found to be 31'1 per cent, of the whole mass. 



The soluble part, which is supposed to be the pimelite, being so- 

 intimately mixed with the insoluble impure sand, I analyzed 

 quantitatively with the following result : 



Silica 45-93 per cent 0=24-49 



Magnesia 34-44 percent 0=13-771 



Nickeloxid 7-69 percent 0= 1-66 [=25.81 



Water 11-68 percent O=10"38 J 



Which gives the ratios of Si0 2 : RO : : 1 : 1-05. A unisilicate,. 

 which may be represented in this form : (Mg x -f- Ni y -f- H z ) O- 

 Si0 2 . 



If ever the mineral pimelite is found and analyzed in a purer 

 state it may possibly have the above composition ; but the Radnor 

 mineral is a mixture. 



Asbeferrite. This variety of amphibole occurs mixed with 

 cobalt and nickeliferous pyrites on calcite. It occurs abundantly as 

 a secondary product in the iron mine near the Falls of French Creek, 

 Chester Co., Penna. It is mostly on the calcite, but some of it has 

 crystallized within it, giving the calcite a greenish tint. The 

 asbeferrite, when dry, has a faint green color ; if wet, as it comes out 

 of the mine, it appears dark green. The best designation may be 



