210 Min era logica I No tices . 



4. Houghite, (ibid, p. 314.) — Occurs near Oxbow, St. Law- 

 rence Co., N. Y.J and also in Rossie, associated with spinel, from 

 which region specimens were received by Prof. Shepard from 

 Dr. Franklin B. Hough of Somerville. It presents oblong flat- 

 tened reniform concretions, rarely above f ths of an inch long, 

 with botryoidal surfaces, whitish externally and bluish or red- 

 dish white within ; lustre faintly pearly, glimmering. Sometimes 

 has a spinel crystal as a nucleus. H. = 2'5. G.=2-02-2'03. It 

 decrepitates and emits water before the blowpipe, losing 33^ p. c. 

 by ignition. Appears to be a hydrate of alumina and magnesia. I 



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[Houghite has been studied recently by Mr. S. W. Johnson, of 

 the Yale Analytical Laboratory, who finds that it is a pseudo- 

 morph, often of spinel and probably also at times of scapolite ; 

 some of his specimens are spinel crystals (octahedral) in one part, 

 and true Houghite in another, and all conditions of change are 

 well illustrated by them. Mr. Johnson is still engaged in his 

 investigations on the subject.] 



5. Marasmolite^ (ibid, p. 315.) — From the feldspar quarry near 

 Middletown, Ct,, along with colurabite, pitchblende and albite. 

 Monometric, with cubic cleavage; color brownish black, and 

 streak reddish brown; brittle; H,^3-5; G. = 3-73-3*74. Com- 

 position, according to Prof. Shepard : 



Sulphur 38-65 Zinc 49*19 Iron 12-16 



affording the ratio 5:3: 1, and the formula 3Zn S + ^e S^- 

 The name is from ftaQarr^iog^ decaying. — [The marasmolite, ac- 

 cording to the writer's examinations of Prof. Shepard's specimen, 

 is a brittle, partially decomposed blende, containing free sulphur 

 in minute points throughout it, as seen with a glass. This free 

 sulphur accounts for the excess in the analysis; allowing thus 

 for a small excess, the composition will become 3ZnS + FeS; 

 which is the formula of the marmatite variety of blende.] 



6. Calyptolite, (ibid, p. 316.) — From Haddam, with chryso- 

 beryl, garnet and beryl ; also from the feldspar quarry near Mid- 

 dletown. Crystals minute, and usually square prisms with pyra- 

 midal terminations; surfaces not smooth and often somewhat 

 concave; color dark brown ; lustre adamantine ; opake. H.=6"5. 

 G. = 4'34. B.B. in an open tube, yields moisture, having an acid 

 reaction, and becomes pale yellowish white; alone, whitens but 

 does not fuse; does not fuse readily with soda; with borax dis- 

 solves slowly into a glass which is yellow while hot, but colorless [ 

 on cooling. When heated in powder with sulphuric acid for | 

 some time, it appears to be completely decomposed, and the glass i 

 tube exhibits corrosion. " The quantity of the mineral was too i 

 small for a satisfactory examination ; but the absence of silica, 



lime, magnesia and alumina was ascertained; and the probability , 



that the substance is a fluo-golumbate of some of the less com- 



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