1895.] Mineralogy. 151 
the prism and clinal pinacoid, the prism angle being 126° 6’. The 
axis of greatest elasticity a makes an angle of 11°-13° with ¢, prob- 
ably in the obtuse angle. The pleochroism is very strong with « sky 
blue to dark blue,» reddish to purplish violet, and « yellowish-brown 
to greenish-yellow. The absorption formula is «>>>. The strea 
is pale blue. G==3.126-3.16. Below are quoted the analyses of glau- 
cophane (I), Riebeckite (II), and the Berkeley amphibole (IID) for 
comparison : 
SiO, AlO, Fe,0, FeO MnO MgO CaO Na,O K,O Total 
I. 55.64 15.11 3.08 6.85 .56 7.80 2.40 934 —— 100.78 
i 500i -—-— 9820 087, 68, 84. 182.879 .72 99.98 
III. 55.02 4.75 10.91 9.45 trace 9.30 2.38 7.62 .27 99.70 
Optically the mineral is almost identical with the amphibole de- 
scribed by Cross from Custer Co., Colorado, and it is closely related 
to Riebeckite. Chemically it is intermediate between Riebeckite and 
glaucophane. 
Willyamite. Pittman? gives the name Willyamite to a sulphantimo- 
nide of cobalt and nickel from the Broken Hill mining district of 
New South Wales, having the formula (NiCo) S (Co Ni) Sb, cobalt 
and nickel being present in nearly equal amounts. 
Kylindrite. Frenzel’ describes a new mineral from Mina Santa Cruz 
at Poopó, Bolivia, which is notable as well for its unusual chemical 
composition as for its crystal form. Analysis furnished the following 
results : 
Pb Ag Fe Sb Sn S Total 
35.41 0.62 3.00 8.73 26.37 24.50 98.63 
which correspond to the formula Pb,Sb,Sn,8, or 6PbS, Sb,S, 6SnS,, 
the silver and iron replacing the lead. The mineral receives its 
name from the remarkable cylindrical rods in which it appears. On 
grinding these in the mortar they separate into concentric cylin- 
- drical shells. A few minute needles which were found in a cavity 
show the symmetry of the mineral to be orthorhombic, The lustre is 
metallic, the color dark leaden, and the streak black. H—2.5 and 
G—5.42. The mineral is soluble in hot hydrochloric and nitric acids, 
and melts in the closed tube with the separation of sulphur. 
Wm. H. Hoss. 
8 Rec. Geol. Surv., New South Wales, iv, pt. i; pp. 21-22, 1894. 
* Neues Jahrbuch f. Mineralogie, ete., 1893, II, pp. 125-128. 
