26 



ROYAL SOCIETY OF CANADA 



ACMITE (^GEKTE). 



The occurrence of this mineral at the Corporation Quarry was called 

 attention to by the writer many years ago, but no analysis was then 

 made. The specimen recently examined was from a segregated vein 

 in the nepheline-syenite composed of a number of minerals, including, 

 in addition to the acmite, nepheline. plagioclas, sodalite, cancrinite, 

 lepidomelane, minute crystals of zircon, small quantities of purple fluo- 

 rite, honey-yellow sphalerite and galena. There are also occasional 

 specks of a mineral which resembles in appearance the variety of thorite 

 known as orangeite, but which has not yet been examined. The acmite 

 occurs in the form of deeply striated prisms, mostly of a greenish black 

 colour, 'though occasionally brown externally and greenish-black within. 

 It has a sub-vitreous lustre and is nearly opaque. The hardness is 

 nearly 6 and specific gravity 3-531. The analysis of the greenish-black 

 material is given under 'I., while II., III. and lY. are quoted for com- 

 parison : 



The Montreal mineral fuses easily and quietly to a black magnetic 

 glass. As yet it has not been studied optically. It has been termed 

 acmite, the general name of the species, but its characters and mode of 

 occurrence appear to be those of the variety œgirite. 



^ " -.Egerin " from elseolite-syenite of Barreros, Brazil. Machado, Tscherm. 

 Mitth. N. F.9, 333. 



* " -^gerin " from Langesundf jiord. Ramm., Pogg. Anal., 1858. 



' " ^gerinaugit« " from cancrinite-nepheline-syenite of Sarna. Rosenbusch, 

 Elemente der Gesteinslehre, 1901, p. 125. 



