Arizona republican., 1909-02-25

inch cubes were found to average 221 grains. or 14S35 grammes in weight, and to absorb as much as 75 per cent of their weight of water. When wet, the material loses its whiteness and assumes D mottled greenish- gray color.
 The determinations were made upon specimens from one of the lower coarser layers.
 Although to the unaided eye there is no apparent difference in the size of the particles from the different levels, all the specimens being white and soft, yet the touch reveals some coarser grains; and particles of grit are found when a block is cut by a saw and there is evidently a consid- erable difference in the degrees of fineness at different levels. By brushing the surface with a soft brush, the finer particles are gradu- ally removed, and the coarser are left standing in relief, palpable to the touch and visible through a pocket lens.
 Under the microscope, the material is seen to consist, for the most part,
  It is apparently a volcanic ash or dust-or, rather, a communicated vol canic glass-in minute transparent angular flakes, generally not more than 0.1 mm, but ranging from 0.1 down to O005 mm., and averaging, perhaps, about O.05 nm. in diameter. Here and there in the mass. as spread out in the field of the microscope, s.T, s-l,s dark green color by transmitted light These may be bits of obsidian, or possibly augite or hornblende. Since they can be readily concentrated by levigatiOn, they are clearly heavier than the colorless glass-like particles There are also small scales, appar- ently of a silvery mica
 Chemical analysis shows nearly SS per cent of silica. In the midst of the volcanic dust the higher powers of the microscope bring into view the beautiful forms of the siliceous re- mains of diatoms.
 Fossil bones of some large animal are reported to have been discovered in these beds. (Pool)
 Diatomite and the associated vol canic ash have a variety of economic uses. Diatomite (known also as in fusorial earth, or diatomaceous earth, and by the Germans as kieselguhr) is usually classed among the abrasives, such as tripoli, rotten-s stone. etc It is largely used as a polishing powder. The white earth from near Carson. Nevada, sold under the trade name of Electro Silicon" is an example The Arizona earth, if cleaned by elutria- ton from coarser metals, such as grit and the larger flakes of volcanic glass, makes an excellent polishing powder for metals. including silver.
 Its use in the manufacture of dyna- | mite as an absorbent dope" for nitro | glycerine is well known. It has been | successfully employed as a non-con- l ductOr of heat for coating steam i pipes and boilers; and could doubt ! less be used to advantage in the | manufacture of safes. It is applied | in coating steam pipes by the Cali | fornia Anti-Caloric Co, and is valued | for that market at S9 per ton under | ground at the mine, and SIS per ton | at the works in San Francisco. In | 1897, a deposit was opened at Lom- poe, Cal, and about 800 tons were shipped from there.
 The production of diatomite in the United States ranges in the neighbor- hood of 5000 tons annually. { For further information Of the earth. and of the new species of diatoms, reference is made to descriptions with illustrations in the Transactions of the Wisconsin Academy of Sciences, June, 1902.
 DIOPsIDE.
 With specular iron, Chiricahua Mts
 DIOPTASE.
 Emerald copper, silica 3S.2, copper oxide 50.4, water 114
 This beautiful gem-li5e copper sili- cate has been noted at several Iocali- ties in Arizona. Its occurrence near Riverside, in Pinal county. was ob- served by Mir. W. B. Smith CPro- ceedings of the Colorado Sci. Soc, Vol. 1T. p. 159, 1SS7) It there oc- CUTS in seams and crevices of the copper ores at one of the shafts of small but numerous, brilliant and high colored.
 Its occurrence was also noted in 1882 at the Bon Ton mines, Chase creek, near Clifton, by R. c. Hills. anu 14llltDTdIu report us occurrence in good crystalline speci- mems at an old dump of the Stevens group of mines on the west side of Chase creek near Garfield gulch These vrystals were from a small of chrysocolla ore in lime stone worked out. This is believed to be the same locality observed by Mir. Hills. According to Penfield to whom some of these crystals were submitted, the crystals, closely group ed together, measured from one milli- metre to two millimetres in diameter in cavities in a brown ferruginous |, gangue impregnated with amorphous ] green material, probably chryocolla. The habit of the crystals is that most ( commonly observed and is especially ] for dioptase. A sample of copper ore containing . diOptase was received for the St ( Louis exhibition from Mir. Messeger of Glendale, in 1863. It came from l