466 PROCEEDINOS OF THE NATIONAL MUSEUM. vol.49. 



land,* and on excursion A 5 of the XII International Geological Con- 

 gress in Canada, 1913, rocks identical in every respect with the present 

 material were observed in connection with some of the serpentine 

 masses in the asbestos region of Quebec. 



The micaceous constituent of the rock can be seen under the hand 

 lens to be partly colorless, but in certain zones it has a brilliant 

 emerald-green color. In thin section both show the optical properties 

 of muscovite, but the green material has in addition the intense pleo- 

 chroism, greenish blue to emerald green to pale green, characteristic 

 of fuchsite. A sample of the rock was treated with hydrochloric acid 

 to remove dolomite and with a heavy liquid (acetylene tetrabromide, 

 diluted with benzene) to remove the quartz. The mixture of micas, 

 containing, as estimated with the microscope, about 10 per cent of the 

 green variety, was fused with sodium carbonate and the chromium 

 determined colorimetricaUy, the result being 0.33 per cent CraOg. The 

 green mica therefore contains approximately 3 per cent of Cr203, or 

 14.4 per cent H2K (CrSi04)3. 



Fuchsite from Marble, Colorado. — A specimen of a bright-green 

 micaceous mineral was collected by Dr. George P. MerriU at the marble 

 quarries of Colorado in 1914 and turned over to the writer for exami- 

 tation.^ In his report on these quarries Doctor Merrill states: 



In the face of the cliffs between quarries Nos. 2 and 3 there occurs for a short dis- 

 tance a bed of white marble traversed by green veins. This is a purely local phe- 

 nomenon due to the presence of a small amount of chromiferous mica and not to 

 copper carbonate, as popularly supposed. 



By dissolving out the inclosing marble with very dilute hydro- 

 chloric acid an mtense green micaceous powder was obtained, which 

 under the microscope appeared to be homogeneous and showed a most 

 brilliant pleochroism. A sample was tested colorimetricaUy for chro- 

 mium and 6.08 per cent CrgOg obtained, which corresponds to 29.2 

 per cent of HgK (CrSi04)3. 



TRIPHYLITE FROM A NEW LOCALITY NEAR GRAFTON, NEW 



HAMPSHIRE. 



The material described in this note was sent personally to Dr. 

 George P. Merrill by Mi-.L. Clough, of East Concord, New Hampshire.^ 

 It consists of a duU gray massive mineral with a greasy luster, showing 

 blue films on joint planes, due to incipient alteration, and is penetrated 

 by narrow veins of crystalluie red garnet and black biotite. The 

 locality is stated to be a mica prospect on the farm of N. M. Kilton, 

 about 4 miles from Grafton station, several miles from the formerly 

 famous locality of triphyhte, graf tonite, etc. Several hundred pounds 

 of it were obtained. 



A sample was submitted by Doctor MerriU to J. E. Whitfield for 

 analysis and his results are given in column 1 below. For comparison 



» Williams and Gill, Johns Hopkins Univ. Circular No. 85, 1889. 

 2 Cat. No. S8332, U.S.N.M. 

 8 Cat. No. 88253, U.S.N.M. 



