G. F. Kunz — Mineralogical Notes. 477 



a rapid disintegration unless the iron is coated with varnish or 

 some other preservative. Even small fragments have already- 

 become seamed, suggesting that the fall is recent. " Microscopic 

 sections were prepared, and in the ground-mass of metallic iron 

 were seen clear crystals of anorthite and olivine. The former 

 are transparent, with inclusions of glass having fixed gas bub- 

 bles, and of many needle-shaped rnicrolites, and some of larger 

 size. The former rnicrolites are probably enstatite, while some 

 black quadratic sections may be chromite>or magnetite. The 

 twinning bands of the anorthite are sharp and distinct. The 

 olivine crystals have greenish, brownish veins of alteration 

 (perhaps induced by the lawrencite) with inclusions of glass, 

 rnicrolites and an abundance of black grains of picotite (see fig- 

 ure 2). These grains are occasionally arranged symmetrically 

 around the crystals as a border, outside of which is usually a 

 grayish, partly opaque mass between the crystal and the me- 

 tallic iron. This grayish mass is an alteration of the olivine 

 which in many cases has taken place in the entire crystal and 

 in others leaving only a small center of clear olivine." 



To Mr. J. H. Caswell the writer is indebted for the above 

 microscopical data and to Mr. Moritz Fischer for information 

 and assistance in procuring the pieces of the meteorite. 



Aet. LIV. — Mineralogical Notes] by George F. Kunz. 



1. Hhodochrosite from Colorado. 



Ehodochrosite in rich red, transparent crystals has been 

 found in the John Reed mine at Alicante, Lake Co., Colorado. 

 One specimen shows forty crystals lining a cavity 8 cm in width ; 

 these crystals are simple rhombohedrons (I?), 12 mm across, a 

 number of them being entirely transparent. Some cleavage 

 pieces are as pellucid as red Iceland spar and show the same 

 strong double refraction. One of them measured 10 mm by 20 mm 

 and weighed 2 grams. This is the first locality that has yielded 

 crystals of such magnitude and transparency. The specific 

 gravity is 3'69 and the hardness 3 5; it is not scratched by 

 calcite but is by Bilin aragonite. An analysis, by Mr. James 

 B. Mackintosh, yielded the following results : 



MnO 58-325 



FeO 3-615 



CaO none 



MgO trace 



CO 2 by difference 38-06 



100-00 



