Chemical Examination of Algerite. 103 



Art. XI. — Chemical Examination of Algerite, a new mineral 

 species ; by T. S. Hunt, of the Geological Commission of Can- 

 ada: including a description of the Mineral, by F. Alger, Esq. 

 (Read before the Boston Society of Natural History by John 

 Bacon, Jr., M.D.) 



The mineral here described was placed in my hands by Mr. 

 Alger, more than a year since, with the following description. 



" It is found in the town of Franklin, Sussex county, New 

 Jersey. The crystals are imbedded in a white crystalline lime- 

 stone, and are without any accompanying minerals excepting a 

 few disseminated scales of graphite. They are occasionally two 

 inches in length and rarely three, and are never more than one- 

 eighth of an inch in thickness. Like sillimanite and scapolite 

 they are frequently curved. They occur as single individuals 

 and never in groups or radiating masses. When taken from near 

 the surface, the color is a deep brownish-yellow, which is evi- 

 dently due to their partial decomposition. Those found at the 

 depth of twelve inches or more, are yellowish-white or straw- 

 yellow, sometimes with a greenish shade ; in a few instances I 

 have found them perfectly colorless and possessing a good degree 

 of translucency. Even the dark yellow crystals, when not de- 

 composing, are slightly translucent, and they then bear a striking 

 resemblance to chondrodite, with which the mineral, when first 

 obtained in a few fragments, was supposed to be identical. It 

 has also been referred to scapolite and spodumene, but it differs 

 from both of these in form and hardness, as well as in other 

 essential characters. In fact its hardness is even inferior to that 

 of laumonite in fresh crystals." 



"I believe that Prof. Nuttall was the first mineralogist who 

 expressed the opinion that this mineral might prove to be a new 

 species, but I am not aware that he ever entered into any investi- 

 gation of its character to satisfy himself upon this point, and for 

 the last ten years, it appears to have been entirely overlooked, 

 the locality even not having come under the cognizance of any 

 mineralogist since his visit to it, until recently explored by my- 

 se 'f. The crystals are rhombic prisms ; the faces M and II' in- 

 dining to each other at an angle of about 94°, as determined by 

 the common goniometer. In no case have I found an individual, 

 having distinct terminal or basal planes by which to determine 

 the angle of P on M, but an oblique termination of the prism is 

 clearly indicated both by its natural joints and cleavage, so that 

 we have an oblique rhombic prism as the primary form ; the 

 accurate measurements of which, farther examination must de- 

 termine. None of the faces are sufficiently brilliant for the reflec- 

 tln g goniometer, although the imperfect cleavage surfaces which 



