106 ANNUAL, REPORT OF THE Off. Doc. 



REPORT OF MINERALOGIST. 



Bv Col. H C. Dfi.MMlXG, Harrisburg, Pa. 



The coi'i-espoudeuce on mineralogy alone during the year 190G 

 exceeded one thousand letters. Inquiries came from many other 

 states and countries. The following is a sample from Iowa: 



"Can you refer me to localities in Pennsylvania where large de- 

 posits of quartz sand or a good grade of building sand can be found? 

 It is my desire to locate such a deposit for the purpose of establish- 

 ing an industry for the manufacture of sand lime brick. The sand 

 for this purpose should be high in the percentage of silica, and 

 should be sharp and free from loam." He. was informed of more 

 than fifty localities. He has also written that he wants 1,00U,000 

 cubic yards of sand with which to start operations. 



Another gentleman came to Harrisburg from New York City in 

 "search of 18,000 tons of first-class building sand. He also was re- 

 ferred to numerous localities. 



In the same line was an inquiry from a corporation manufacturing 

 window glass. Judging by the tone of the correspondence they con- 

 sume a trainload of glass sand every working day at their seventeen 

 different jjlants. 



During the year numerous other inquiries were made for silicates 

 similar to the aforementioned, and all the inquiries answered satis- 

 factorily except in one instance, that for a large deposit of loess. 

 Loess is mentioned in but few standard authorities on mineralogy 

 or geology, and any information respecting it is very unusual. It is 

 a fine earthy deposit, mostly silica, following the courses of valleys 

 or streams, like alluvium, but without division into thin layers. One 

 of its constituents is invariably a calcareous material, generally in 

 concretions. It is most frequently found in elevated terraces along 

 the broad parts of large valleys, as on some parts of the Delaware 

 and Biisquehanna rivers; but the fine particles of coal which are 

 carried down our largest streams, lodging with or on the loess, have 

 destroyed these deposits for commercial use, viz: the manufacture 

 of cement or similar products. Portland cement, which has now be- 

 come essential in the making of concrete or artificial stone, origin- 

 ated in England by the mixing of TO per cent, of chalk with 80 per 

 cent, of the alluvial clay or mud within the lower tidal basins of the 

 Thames and the Medway, the mud supplying the silica and alumina 

 in proper condition, and the chalk the calcium carbonate or lime. 

 In this connection there has been serious talk of forming a cement 

 (rust. It is doubtful whether such a combination can long exist in 

 Pennsylvania, as in nearly every county of this Commonwealth can 

 be found all the necessary constituents of the best hydraulic and 

 Portland cements. 



In(|uiry is made for deposits of asbestos. The locations of the 

 mineral have been mentioned in former reports. There is an in- 



