440 Wright and Larsen — Quartz as a Geologic Thermometer. 



Specimens used in Table VI. 



1. White vein quartz. Auburn, Maine (U. S. Nat. Mus. Spec. 

 No. 75,530). Specimen of glassy quartz, transparent in spots 

 and comparatively free from fine cracks. Fracturing after 

 (1011) noticeable. 



2. White milky vein quartz in limestone, associated with galena 

 and sphalerite. North Arm, Moira Sound, Prince of Wales 

 Island, Alaska. (Charles W. Wright, collector.) 



3. Quartz crystals. Forms: (1010), (lOll), (0111), (1121), 

 U. S. Nat. Mus. No. 45,205). Crystal Mt., near Hot Springs, 

 Arkansas. Clear, transparent crystal groups. 



4. Large quartz crystal traversed by shearing planes almost at 

 right angles with principal axis. Parts of crystal clear and 

 transparent. Locality unknown. 



5. White vein quartz near Canaan, Conn. Yein occurs in 

 'metamorphosed Cambrian limestone directly overlying Ver- 

 mont quartzite. Quartz is associated with tremolite. (A. C. 



. Spencer, collector.) 



6. Quartz vein in Cheshire quartzite, Ashley * Falls, Mass. 

 White, transparent in spots. Occasional flakes of muscovite 

 occur in this quartz. (A. C. Spencer, collector.) 



7. Quartz associated with magnetite and garnet. Lover's Hole, 

 Barton Hill, N. Y. Quartz is fairly massive and clear in 

 spots. (A. C. Spencer, collector.) 



8. Vein quartz. Group of crystals (1011), (01 1 1), (1010. 

 Glacier Basin near Wrangell, Alaska. Zonal structure well 

 developed. Crystals massive. (Fred E. Wright, collector.) 



9. Vein quartz in Precambrian schists. Sugar Loaf, Md. 

 Crystals bounded by (1010), (1011), (0111). Rhombohedral 

 development prominent. In general quartz is milky in color. 

 Small crystals are transparent. This group contains speci- 

 mens from three different veins a mile or more apart in the 

 schists. (E. S. Larsen, collector.) 



10. Quartz crystal. Herkimer County, N. Y. Doubly terminated 

 crystal (1010), ( 1 011), (0111), occurring in metamorphosed 

 limestone. 



11. Rose quartz. New Milford, Conn. (U. S. Nat. Mus.) 

 Massive and comparatively clear quartz. 



12. Rose quartz from quarry P. H. Kinkle's Sons, Bedford, N. Y. 

 Occurs in large pure masses in coarse pegmatite, associated 

 with large masses of pure feldspar, both minerals grading 

 into graphic intergrowths ©f feldspar and quartz. Spec. 753. 

 (E. S. Bastin, collector.) 



13. Rose quartz. Paris, Maine. (U. S. Nat. Museum.) Massive 

 and clear rose-colored quartz. 



14. Rose quartz. Maine. (U.S.Nat. Museum.) Massive and 

 pale rose-colored quartz. 



15. Smoky quartz. Berry feldspar quarry, Poland, Maine. 

 Crystals project inward from walls of gem-bearing pockets 



