480 W. WM. Foote—Note on a new Alkali Mineral. 
Art. LIL—Preliminary Note on a new Alkali Mineral ;* 
by WARREN M. Foote. 
WHILE searching recently at Borax Lake, California, for the - 
new species sulphohalite,t Mr. C. H. Northup discovered 
small crystals of what he considered to be a new form of that 
mineral.. Mr. Northup reports that they are very rare, having 
been found during a laborious working of the “tailings” or 
debris from an exploratory boring known as the “ New Well,” 
made by the Borax Lake Mining Company, and that they were 
undoubtedly formed in a stratum of clay reached at a depth of 
about 450 feet. 
The entire find was forwarded to Dr. A. E. Foote, to whom 
the writer is indebted for the material used in this brief exam- 
ination. 
Crystallization, etc—The mineral crystallizes in regular 
octahedrons, whose diameter rarely reach one centimeter. They 
occasionally exhibit triangular markings and a habit of parallel 
grouping in more or less regular aggregates. Fractured erys- 
tals show in the interior a cross of faint lines running perpen- 
dicularly to the crystal faces. These are divided by darker 
planes lying parallel to cubic symmetry, and passing through 
the angles of the octahedron, dividing it into eight parts. The 
same thing is noticeable in the clearest of the complete erys- 
tals, a bundle of strize coming from the center of the crystal 
to the center of each face with the dividing planes clearly visi- 
ble. This phenomenon is strikingly similar to that observed 
in cubes of boléite (figured by Bombicci in a memoir on 
mimetical pyrite, Bologna, 1893). The markings in the pres- 
ent instance are probably due to inclusion of organic matter, as 
in chiastolite. 
The color varies from dirty white, pale yellow and greenish 
gray to dark brown; the lighter colored crystals closely resem- 
ble senarmontite. Cleavage is imperfect. It is brittle and 
shows uneven fracture. Luster, vitreous on broken surfaces, 
occasionally bright on crystal planes. Hardness, 3°5 to 4. 
Chemical examination.—In powdering the mineral a fetid 
odor is distinctly perceptible. It is easily fusible before the 
blowpipe; in the closed tube it blackens and gives off a burnt 
odor with violent decrepitation and liberation of water (which 
subsequently proved to be mechanically included), finally fus- 
ing toagray mass. Boiling water effects partial decomposition 
of the powdered mineral, with separation of a bulky white 
* A revision of a paper read before the meeting of the Philadelphia Academy 
of Natural Sciences, Aug 27th, 1895. 
+ This Journal, xxxvi, p. 463. 
