34 
The N.Z. Journal of Science and Technology. 
[Jan. 
Clay , China.-—See Kaolin. 
Clay, Common.'—Used for cement, common bricks, vitrified bricks, tiles, 
terra-cotta ware, as a lubricant (emollient), filler (paint, &c.), adulterant, 
and in ropemaking. , Used also for cleaning (pipeclay), as a mortar, 
for adobe buildings (made of sun-dried bricks), for wattle-and-daub 
huts, for dams, and many other purposes. 
Claystone.— Used for cement, bricks, tiles, &c. See also Clay, Shale, Slate. 
If calcareous, may be used as a soil-dressing. 
Coal .■—Not only is coal man’s principal source of artificial heat and power, 
but numerous industries employ coal-products as essential materials. 
The most noteworthy of these are those using coal-tar products (aniline 
dyes, &c.), ammonia and ammonium sulphate, and other important by¬ 
products of coal. 
Copper-ore.' —Manufacture of copper and copper-alloys, and of numerous 
salts used in the arts and manufactures. 
Diatomaceous or Infusorial Earth.- —Used as an absorbent for nitro-glycerine 
in the manufacture of dynamite ; as a heat-insulator for covering 
boilers and steam-pipes, and for protecting refrigerating-chambers ; as 
a fireproofing material ; as a soundproofing material ; in manufacture 
of polishing-powders (Tripoli powder), scouring-soap, pottery, bricks, 
and sodium silicate (soluble glass) ; as a filtering-material, and as 
material for asphalt pavements. 
Dolomite.- —Used as a refractory lining for steel-furnaces, as a flux in metal- 
smelting, and in manufacture of whiting. When calcined or ground 
it may be used, notwithstanding its high magnesia-content, as a sub¬ 
stitute for ordinary lime, both for making mortar and, under certain 
conditions, as a soil-dressing. 
Feldspar, Potash.-—Used (when ground) in the manufacture of cement, 
pottery, some classes of tiles and bricks, enamel-ware, glass, artificial 
stone, scouring-soap, and as an abrasive. A special quality is used 
in making dental porcelain. May also, if finely ground, be used as a 
fertilizer (on account of potash-content). It may also be possible to 
make potash salts from feldspar on a commercial scale. 
Feldspar, Soda, Soda-lime, and Lime.-—May be used for some classes of 
pottery and glass, for artificial stone, scouring-soap, abrasive pur¬ 
poses, &c. 
Fireclay.—Used for making refractory bricks (firebrick, &c.). Some fire¬ 
clays may be used for pottery. 
Flint.- —-Pebbles, if moderately round in two directions, are used in tube 
mills for the fine grinding of quartz (gold-ores), limestone (cement- 
works), &c. Calcined and ground flint is used in pottery-manufacture 
(one purpose being to render somewhat fusible clays less fusible), in 
glass-manufacture, &c. 
Fluorite (or Fluor-spar).—Used in manufacture of glass, porcelain, enamel, 
and some kinds of pottery (sanitary ware), and as a flux in metal- 
smelting, especially for iron-ore. Used also in the manufacture of 
aluminium (as a flux), of hydrofluoric acid, of sodium fluoride, and of 
cyanamide. 
Fuller's Earth. —A special kind of clay. Used in papermaking, and as a 
decolorizing, deodorizing, clarifying, and filtering agent in the cleansing 
of woollen goods, in soap-refining, in oil-refining, &c. Is an absorbent 
for grease, &c. 
Ganister. —Practically a somewhat fine-grained sandstone. Used in making 
refractory firebricks. 
