70 G. J. Brush’s Mineralogical Notices. 
‘ 
the unionite a Silliman. We had no reason to doubt the 
be 
authenticity of o een as they were collected at. the 
by Silliman. B.B. fuses easily, with intumescence, ane em 
with a white light. To the tube yields water. Sp. gt 5-299. 
of 1:036 grams fused wk carbonate of soda gave :— 
xygen 
Silica, 40°61 21-10 3 
i 15°63 2 
Sesquioxyd of iron, 0°49 15 
Lime, — 8 6°86 1 
a 
Ignition, 2°22 
The oxygen ratio is that of f epidote, and the analysis agrees 
with Rammelsberg’s analyses* of zoisite. Its physical charac- 
ters are also identical with zoisite, and it forms one of the purest 
varieties of lime-epidote. 
4. Feldspars from the Danburite locality. 
Prof. J. Lawrence Smith and myself have shown} that dan- 
burite is associated with both orthoclase and oligoclase. This 
locality has been re-opened during the past year, and the feld- 
spar now obtained there is aie orthoclase. tt forms a vein 
in dolomite from one and a half to two feet in width, and oceurs 
in broad cleavable masses as well as in the more compact gran- 
ular form before observed and analyzed by Smith and myself. 
The cleavable variety has recently been analyzed by Mr. Geo. 
¥. Barker of the Yale Scientific School, with the following result: 
Si Al a Na Ign. 
Sp.gr.258. 6425 1880 120° 1244 240 0-30=99°39 
- The Basser of danburite which were taken from the lo- 
calit: ears since, and from a part of the vein ren vey 
