The specimen of Upper Bunter Sands, in which this magnetite occurs, was collected at Hinksford (Staffordshire), near Stourbridge. It is a white, very loosely coherent sand of medium grain ; and contains, as was found by separating the constituents in mercury-potassium iodide, turbid orthoclase, microcline, fragments of the micro-crystalline ground-mass of acid lavas or intrusive rocks, quartz, staurolite, tourmaline, garnet, zircon, rutile, muscovite, a little haematite, and abundant magnetite.

The grains of magnetite are very minute, averaging 0.067 mm., but nevertheless they present, with very few exceptions, a perfect crystal outline, that of a simple cube, or, in a few rare cases, that of a regular octahedron.

Baumhauer, 1896, Zeits. Kryst. Min. XXVI, 598-602. Crystallography. with Analysis by Bömer. (Abstract Min. Mag. XI, 225.)

Jackson, 1900, Min. Mag. XII, 287. Analyses.

System : Rhombic. a : b : c = 0·4782 : 1 : 0·5112.

These ratios are calculated from 010 : 350 = 51°7′ and 010 : 111 = 70°45′ measured On crystal No. 1 (see p. 81). A new orientation has been chosen for the crystals, so that the well-developed prism zone is vertical, and the cleavage plane, (001) of Baumhauer, becomes (010) to correspond with the cleavage of jordanite. The parametral plane has also been changed, chiefly on account of the pyramid planes.

In connection with the investigation of ægirine-anorthoclase rocks from Abyssinia, belonging to the grorudite-tingusite series, an examination was made of specimens of the so-called green phonolite from Elfdalen, which in the British Museum collection accompanied the more ordinary brown and red porphyry from that locality. In the descriptions of the well-known porphyry quarries of Elfdalen, mention is made of this green variety as occurring only in boulders. Törnebohm was the first to record the occurrence of these rocks in situ, and to describe their characters, They were found in the form of dykes in the neighbourhood of Heden, near Särna, Dalarne, Sweden, and were interesting as containing cancrinite in clear, well-defined porphyritic crystals as undoubtedly a primary constituent.

The new mineral to be described occurs as veins and as nodules of considerable size in the mines of the Borax Consolidated Company, Limited, situated in the Mohave Desert, sixteen miles north-east of Daggett in San Bernardino County, California. The white, amorphous masses resemble in appearance unglazed porcelain or fine white marble. Sometimes the mineral has a faint tinge of a sea-green colour. Its hardness is about 41/2 and specific gravity 2.73. Up to the present time no specimens showing any signs of crystallization have been noticed. In external appearance the mineral shows a striking resemblance to the pandermite of Sultan Tchair in Asia Minor, and it may be here noted that this amorphous variety of calcium borate occurs also in the Californian mines.

The geological features of the immediate neighbourhood of the Santa Fé Mine, which is situated about nine leagues nearly due east of the departmental town of Pichucalco, have been partially described by the author in a paper recently read before the Institution of Mining and Metallurgy. The key to the position, from the point of view alike of mineralogical and of economic interest, is found in a dome-shaped mass of wollastonite in a nearly pure condition, the horizontal section of which, at the lowest level where it has been sufficiently explored to determine its shape, takes the form of an irregular ellipse about 400 yards long by 160 yards wide. With the exception of the ore-bodies, which are developed on the outskirts of this mass and close to the contacts with other rocks, the whole mass is of nearly uniform composition, consisting of the mineral wollastonite in a nearly pure condition and very coarsely crystallized.