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Mr. Francis Alger exhibited some very beautiful specimens 

 of Zincite or red oxide of zinc from Mine Hill, Franklin, 

 Sussex County, New Jersey. 



The analysis of a very pure specimen, by Mr. Wm. P. Blake, gives 

 99.47 per cent, of oxide of zinc, and .68 of oxide of manganese. The 

 exact locality from which it was obtained could not be ascertained, and 

 it is probable that very few specimens of such purity will be hereafter 

 seen. It is very interesting to mineralogists, and very important in 

 its economic application, as affording the pure white zinc paint of 

 commerce. It was first analyzed and named red oxide of zinc by 

 Dr. Bruce, of New York, in 1810 ; but his specimen must have been 

 an impure one, as he obtained only 92 per cent, of oxide of zinc and 

 8 per cent, of peroxide of iron and manganese ; the impurity was 

 doubtless FrankHnite. 



Berthier's analysis, some years later, was made from a still more 

 impure specimen, and yielded only 88 per cent, of oxide of zinc, and 

 yet in some mineralogical works it has been made the basis for its 

 atomic formula. There has been great difference of opinion as to 

 the nature of the coloring matter which gives the deep red or ruby 

 hues. Until 1844, the color was attributed to red oxide of man- 

 ganese ; but Dr. Hayes at that time made an analysis of a very pure 

 specimen, and established, as he believed, the two important facts, 

 that the red color is not owing to the presence of manganese, and 

 that this metal does not exist as red oxide, but simply as protoxide ; 

 he believes that the peroxide of iron alone imparts the red color. 

 Prof Rose, of Berlin, made an analysis in 1847, and found 96.19 per 

 cent, of oxide of zinc and 3.70 of oxide of manganese, and decided 

 that the color is due to the latter, which is unessential except as far 

 as color is concerned. Mr. Blake separated the manganese from the 

 zinc by means of bromine, and found it to contain only a trace of 

 oxide of iron ; he attributes the color to the manganese. 



It is evident that the mineral is simply oxide of zinc, with a small 

 admixture of manganese oxide, not forming fin atomic proportion, 

 but diffused in the attenuated form of coloring matter. The crystals 

 are hexagonal prisms, of a ruby red color, cleaving readily parallel 

 to the vertical axis. The substance resembles bichromate of potash, 

 chromate of lead, red oxide of silver, but most nearly realgar or sul- 

 phuret of arsenic. Its hardness is between four and five, and its 

 polish and beauty entitle it to rank with the gems ; IVIr. Alger pro- 

 posed for it the new name of Ruby Zinc. 



Dr. C. T. Jackson considered it demonstrated by IVIr. Blake's 

 analysis that oxide of iron was not the coloring matter of ruby zinc ; 

 he approved the name, as also did Prof Wm, B. Rogers, there beino- 

 no red oxide of zinc in nature, and this term not implying that 

 there is. 



PROCEEDINGS E. 8. N. H.— VOL. VIII. 10 AUGUST, 1861. 



