BULLETIN No. 46 
CONTRIBUTIONS TO CANADIAN MINERALOGY, 1926 
By Eugene Poitevin 
CONTENTS 
Page 
A new Canadian occurrence of phosphorite from near Francois lake, British Columbia 2 
Optical properties of chemically analysed ferroprehnite from Adams sound, Baffin 
island 12 
Zircon from Dungannon township, Hastings county, Ontario 14 
Epidesmine from Thetford Mines, Megantic county, Quebec. 15 
Halotrichite from Ashcroft, B.C. 15 
Tremolite crystals from Admaston township, Renfrew county, Ontario 16 
Yellowish barite from Port Arthur, Ontario 16 
Alunogen from Vernon, B.C 16 
Wolframite from Mud creek, Rocher D6boul6 mountains, near Hazelton, B.C 17 
Zircon from Monmouth township, Haliburton county, Ontario 17 
Tourmaline from Bagot township, Renfrew county, Ontario 18 
Seoleeite from Thetford Mines, Megantic county, Quebec 18 
Barite from Madoc township, Hastings county, Ontario 20 
Illustrations 
Plate I. Specimen showing nodular bodies of collinsite and quercyite enclosing 
fragments of andesite. 43 
II. Microphotograph of conical quercyite spherulites from Frangois lake, B.C. 44 
Figure 1, Structure of the phosphate nodules, Frangois lake, B.C. 4 
2. Collinsite from lake Frangois, B.C. Optical and crystallographic elements 
plotted on the stereographic plat of Fedoroff 6 
3. Refractive indices of the collinsite-messelite series 9 
4. Zircon from Dungannon township, Hastings county, Ontario 14 
5. Orthographic and elinographic projections of seoleeite from Thetford 
Mines, Megantic county, Quebec 19 
6. Orthographic and elinographic projections of barite from Madoc town- 
ship, Hastings county, Ontario 20 
7. Orthographic and elinographic projections of barite from Madoc township, 
Hastings county, Ontario 21 
