416 W. P. Headden — New Phosphate from /South Dakota. 



This ratio approaches 1 : 1 and includes the water as basic 

 and the whole of the iron as FeO. If the water be considered 

 as water of hydration, the oxygen-relations cannot be expressed 

 by any simple ratio. If instead of computing the oxygen 

 alone we reckon the atomic equivalents we obtain as favorable 

 a ratio ; for, substituting an equivalent number of bivalent 



atoms for Al 2 vi we obtain for the ratio of P : R : = 1 : 2*49 : 5*18 



instead of 1 : 2*5 :5 or 2 : 5: 10 corresponding to the formula 



i 



P o P.O 10 which is a salt corresponding to the normal phosphoric 

 acid H 5 P0 5 and in which P = (MnCaFeH 2 Xa 2 )f + M\. Other 

 complete analyses, than those given were made of less care 

 fully selected material with closely agreeing results. 



I would propose to call this new phosphate Griphite, from 

 ypiifyos puzzle, in allusion to its unusual and somewhat enig- 

 matical composition. 



A Phosphate near Triphylite from the Black Hills. 



A mineral, associated with beryl and spodumene, occurs in 

 nodules in the granite of the Xickel Plate tin claim, Penning- 

 ton Co., South Dakota. The inner portions of these nodules 

 are nearly free from other minerals while the outer portions 

 contain some small bunches of mica, a few isolated, black, pris- 

 matic crystals, which are brown by transmitted light, and here 

 and there small patches of a light brown mineral with resinous 

 luster, conchoidal fracture and one distinct cleavage. Neither 

 the black crystal nor the light brown masses seem to be derived 

 by decomposition, from the surrounding mass as it is wholly 

 unaltered." 



The mineral forming these nodules, is, in the mass, dark 

 green, in thin splinters, it is translucent to transparent and is a 

 light yellowish green ; it fuses easily on the edges of thin 

 pieces in the name of a candle, to a dark brown, magnetic 

 globule and colors the blowpipe flame a faint yellow. It has a 

 hardness of about 5, a specific gravity of 3*6 12; cleavage in 

 two directions, in one it is perfect in the other it is quite im- 

 perfect and the directions are not at right angles to each other* 

 The lustre is vitreous and the fracture uneven to small con- 

 choidal ; streak and powder very light green, almost white. 

 When exposed to the atmosphere for a short time it darkens 

 externally due to oxidation. The freshest material was taken 

 for analysis which gave the following results : 



* Subsequent examination showed the black prismatic crystals to be crystals 

 of cassiterite with the usual combination of the pyramid and prism, the prism 

 beinsr very strongly developed. Many of these crystals are fretted to such au 

 extent that they form almost skeleton crystals. 



