On two Decomposed Varieties of lolite. 357 



2. Chlorophyllite. — The following description of this substance 

 is abstracted from the " First annual report on the geology of the 

 State of New Hampshire," by Dr. Chakles T. Jackson. 



" ChlorophyUite. — I have given this name to a new mineral found near 

 J. Neal's mine in Unity. The name is derived from the Greek words 

 signifying green folia^ a name which is eminently characteristic of the 

 species. It occurs in tabular, or short six sided prisms, arranged in folia 

 or in columnar masses, resulting from the openness of its natural joints. 

 The extremities of the prisms or tables are often covered with thin lay- 

 ers of mica, which circumstance has caused some mineralogists to mis- 

 take the true nature of the mineral. It cleaves readily into regular six 

 sided prisms, with resplendent surfaces. On trying its hardness it was 

 found to yield to the knife readily, but it scratches glass, and is harder 

 than phosphate of lime. Its powder is of a very pale greenish white. 

 Alone before the blowpipe it glazes slightly on the surface, but does not 

 fuse entirely. It is fusible with carbonate of soda, with slow efferves- 

 cence, and forms an opaque greenish enamel, which becomes of a darker 

 green in the reducing flame. Its specific gravity is 2.705. 



" Mr. J. D. Whitney analyzed a specimen of it in my laboratory, and 

 obtained the following results. One hundred jrrains of the mineral con- 

 sist of 



Water, .... 3.600 



Silica, .... 45.200 



Phosphate of alumina, - - 27.600 



Magnesia, .... 9.600 



Protoxide of ii'on, - - - 8.256 



Manganese, .... 4.100 



Traces of potash, and loss, - - 1.644 



100.000" 



I am indebted to Mr. B. Silliman, Jr., one of the editors of this 

 Journal, for a specimen of this mineral. In handing it to me, he 

 remarked that it had a strong resemblance to the Haddam pinite. 

 Its color is more bluish, however, than that of the Haddam 

 mineral. Its general lustre also is higher, but this is owing to 

 scales of what appears to be silvery mica traversing the chloro- 

 phyllite, both in the direction of its horizontal and vertical cleav- 

 ages. Its hexagonal cleavage is remarkably distinct. It still far- 

 ther differs from the Haddam pinite in presenting points where 

 the iolite remains unchanged, possessing not only its usual blue 

 color, but its characteristic hardness and vitreous lustre. 



