REPORT ON THE DEPARTMENT OF MINERALS 

 IN THE U. S. NATIONAL MUSEUM, 1889. 



By F. W. CLARKE, Honorary Curator. 



In general the work of the year has followed the usual lines with little 

 variation. The only notable divergence was iu the matter of the ex- 

 hibit at the Cincinnati Centennial Exposition, in which the Department 

 was represented merely by a single case of specimens, to illustrate the 

 -cms and precious stones of North America. In the preparation of 

 that exhibit a \'v\v very choice gems were added to the collection. 



The growth of the collection during the year has been highly satis- 

 factory, and especially so as regards the quality of the material obtained. 

 The two most important accessions were received from the U. S. Geo- 

 logical Survey, in collections made by Profs. S. L. Pentield and W. F. 

 Hillebrand, respectively. The Penfield collection was obtained in two 

 seasons of field work in and near St. Lawrence County, Xew York, and 

 numbers 1,366 specimens, of which a considerable number are dupli- 

 cates. It is exceedingly rich in black, brown, and white tourmaline, 

 \\ bite and green phlogopite, diopside, calcite, albite crystals, oligoclase, 

 danburitc, wollastonite, tremolite, etc., and it contained several almost 

 unique specimens. Of the latter I may mention a huge mass of green 

 fluorite, superbly crystallized, a large pyrite crystal, a radiated brown 

 tourmaline, and a series of most brilliant peristerite feldspars. Dr. 

 1 1 illebrand's collection was made during a six weeks trip to the Far West, 

 in which he visited the cryolite locality near Pike's Peak; the Tintic 

 District in Utah: Silver City, Georgetown, and Las Oruces, New Mex- 

 ico; and the Copper Queen .Mine in Arizona. The collection embraces 

 the cryolite groups of minerals, a magnificent series ofinixite, tyrolite, 

 eiinite, and clinoclasite ; some very brilliant and unusual descloizite, 

 finely crystallized wulfenites, and some extraordinary azurites and 

 fibrous malachite. On his journey Dr. Hillebrand also made some pur- 

 chases for the Museum, securing among other things a lot of turquoise 

 from Los Cerillos, New Mexico, numbering 363 specimens, mostly dupli- 

 cates. The descloizite from Georgetown, New Mexico, was ;i new dis- 

 covery, and Mr. Alex. McGregor, manager of the mine in which it oc- 

 curs, has since sent the Museum a superb series of si specimens, m- 

 II. Mis. 224, pt. L' 26 401 



