848 NEW YOEK STATE MUSEUM 



Mineral paint 



By this term is meant a paint obtained by taking some eaxtliy 

 mineral or rock, wliicli has the desired color, grinding it to a fine 

 powder if it is not already in that condition, and then mixing it 

 with oil. 



One of the commonest forms of mineral paint is the well-known 

 ocher which is simply a fine-grained f errnginous clay, of the proper 

 color. Common ocher is not quarried in this state, but a variety of 

 ocher known as sienna is found, forming a thin bed in the glacial 

 drift south of Whitehall, and has been worked for a number of 

 years. 



In the southern part of the state uear Randolph there occurs a 

 series of shale beds which exhibit green, brown, bluish and olive 

 colors, depending on the amount of iron oxid which they contain 

 and its condition of oxidation. These are worked by the Elko 

 mining and milling co., and ground for mineral paint. 



Mineral paints made from clays stiid shales form a cheap and 

 satisfactory form of color application for wooden surfaces. The 

 value of the material depends to a large extent on the shade of the 

 color, the amount of fineness which it naturally possesses and the 

 percentage of oil which has to be mixed with it in order to give a 

 mixture of the proper consistency. 



Clarifying oils and fulling earth 

 Under this head is included the material known as fullers' earth. 

 Properly speaking, fullers' earth is not a clay, because it lacks plas- 

 ticity, but some of the material which is put on the market under 

 this name and does the work required of it as well as true fullers' 

 earth is ordinary plastic clay. 



fullers' eakth 

 Properties and uses. Fullers' earth is one of the most interest- 

 ing materials with which the economic geologist has to deal. In 

 appearance it resembles clay, in properties it differs from it very 

 considerably, in that it usually lacks plasticity, and also has the 



