Quantcast
  Due to a new server, slow response may occur for which we apologize Portal logo
Login/Register
Bactrian Gold Treasure from Afghanistan, coming soon....
/gemstones/feuchtwanger-treatise-stones/page_117 - 2
 

Ch. 3: Minerals: Chemical Properties

Ch. 3: Minerals: Chemical Properties Page of 515 Ch. 3: Minerals: Chemical Properties Text size:minus plus Restore normal size   Mail page  Print this page
CHEMICAL PROPERTIES OP MINERALS.                117
borax. It is also a useful reagent for many silicates, whose silica is separated from the base and remains undissolved in the melted salt. (4.) Solution of cobalt (nitrate of co­balt dissolved in water), or dry oxalate of cobalt, serve as tests of alumina, magnesia, and zinc oxide.
In examining minerals in th*e moist way, the first point to be considered is their solubility, of which three .degrees may be noted : (!) minerals soluble in water ; (2) minerals soluble in hydrochloric or nitric acid; and (3) those un­affected by any of these fluids. The minerals soluble in water are either acids (almost only the boracic acid or sas-solin and the arsenious acid), or oxygen or haloid salts. These arc easily tested, one part of the solution being em­ployed to find the electro-positive element or basis, the other the electro-negative or acid.
Minerals insoluble in water may next be tested with the above acids; the nitric acid being preferable when it is probable, from the aspect of the mineral or its conduct be­fore the blowpipe, that it contains an alloy, a sulphuret, or arseniate of some metal. In this manner the carbonic, phosphoric, arsenic, and chromic acid salts, many hydrous and anhydrous silicates, many sulphurets, arseuiates, and other metallic compounds, are- dissolved, so that further tests may be employed.
The minerals insoluble either in water or these acids are' sulphur, graphite, cinnabar, some metallic oxides, some sulphates, and compounds with chlorine and fluorine, and especially quartz, and various silicates. For many of these no test is required, or those furnished by the blowpipe are sufficient. The silicates and others may be fused with four times their weight of anhydrous carbonate of soda when they are rendered soluble, so that further tests may be ap­plied.
Ch. 3: Minerals: Chemical Properties Page of 515 Ch. 3: Minerals: Chemical Properties
Table Of Contents bullet Annotate/ Highlight
Feuchtwanger. Treatise on Precious Stones.
Suggested Illustrations
Other Chapters you may find useful
Other Books on this topic
bullet Tag
This Page