346 Gihbs on Tourmalines, ire. 



After seeing the notice of the crystals found at Hudson by 

 Mr. Schaeffer, I wrote to a member of the Lyceum of Natural 

 History, New- York, rather more full an account than the 

 above, of my crystal, &c. I hope to ascertain, whether the 

 liquid will congeal at 10 or 20° below 0, but have some fear 

 lest the crystal should be injured. 



CD. 



Art. IV. On the Tourmalines and other Minerals found 

 at Chesterfield and Goshen, Massachusetts, by CoL 

 George Gibes, 



(For the American Journal of Science.) 



X HE schorl of the mineralogists of the last century united a 

 variety of substances which subsequent observations have 

 separated into several species. The green schorl is now the 

 epidote, or the Vesuvian, or the actynolite. The violet schorl, 

 and the lenticular schorl, are the axinite. The black volcanic 

 schorl is the augite. The white Vesuvian schorl is the sommite. 

 The white grenatiforra is the jeucite. The white prismatic 

 is the pycnite, a species of the topaz, and another is a variety 

 of feldspar. Of the blue schorl, one variety is the oxyd of tita- 

 nium, another the sappare, and another the phosphate of 

 iron. The schorl cruciforn is the granatite. The octahedral 

 schorl is the octahedrite, or anatase. The red schorl of Hun- 

 gary, and the purple of Madagascar, are varieties of the oxyd 

 of titanium. The spathique schorl is the spodumen. 



The black schorl, and the electric schorl, only remained, and 

 to avoid the confusion created by the use of the term schorl, 

 the name of tourmaline was given to this species by that cele- 

 brated mineralogist, the Abbe Haiiy.* 



* If this memoir should ever meet the eye of this amiable man, I trust he will 

 excuse the notice to which his labours so justly entitle him. To him we are in- 

 debted for a complete science of crystallography, and for having determined the 

 existence and limit of species, which mineralogists had not obtained, and chemist*" 



