876 A. //. Phillips— N«w Zinc Phosphates. 



and becoming yellow while hot. A sample was tested fur loss 

 of water at various temperatures with the following results; 

 expressed in percentages. 



1 10° 



120° 



140° 



167' 



204° 



■244" 



97 A 



- i a 



Red heat 



•111 



•41 



1-39 



2-8fl 



9-21 



9-65 



9*71 



13*22 



All the above results would indicate that the formula assigned 

 to the mineral is undoubtedly correct. 



flibbenite. — Mr. McBurney very kindly responded to a 

 request for more material with a specimen weighing a little 

 over 500 gms; This specimen was, apparently, a portion of a 

 rounded nodule of radiated spencerite crystals, enclosed also iri 

 a botryoidal crust of Dearly pure white calamine (silicate). 

 Some of the crystals showed cleavage surfaces nearly three 

 inches in length. The specimen was much affected by solu- 

 tion, and was very friable in portions, some laminae being 

 more soluble than others, breaking down into thin scales. 

 Under the hinocular a crystal angle quite different from the 

 spencerite in appearance and slightly yellow in contrast to it 

 was noted. Further search through the specimen yielded 

 eight or ten of these crystals, varying from eight to twelve 

 millimeters in length. These crystals 1 believe to represent 

 another new basic zinc phosphate and 1 sugu"e>t the name hib- 

 benite for it, in honor of Dr. John Grier ELibben, President of 

 Princeton University. 



Habit. — The habit is orthorhombic. tabular parallel to the 

 maeropinacoid, a (100), nearly as broad as long and approxi- 

 mately one quarter as thick along the brachyaxis. as broad 

 along the macroaxis. They are all comhinations of the pin- 

 acoids a (100) and b (010). the prism * (120), the pyramid 

 /'(111) and the macrodome rf(101). The brachypinacoid is 

 the dominant face, yielding the tabular appearance of the crys- 

 tals. Implanted separately upon and evenly distributed over 

 all the crystal faces are small, rounded lens-shaped crystals. 

 They average about oue millimeter across, have no definite 

 orientation to the crystalline directions of the hibbenite or to 

 each other and are so rounded by parallel growths that crystal 

 forms or faces cannot be identified. These small crystals I 

 believe to be also another new basic zinc phosphate. The hib- 

 benite crystals are all simple in habit and separately imbedded 

 in the spencerite. In several instances parallel growths were 

 attached to the terminations and extending out in the matrix, 

 ending in rounded granular stringers. These parallel growths 

 were easily detached, leaving the terminal faces intact, but 

 much pitted and scarred. The brachypinacoid. b (010), is 

 inconspicuous, very narrow and striated parallel to the vertical 

 axis. It occurs on about half of the crystals. The prism, 



