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_225 - 2
 

Ch. 6: Sapphire

Ch. 6: Sapphire Page of 515 Ch. 6: Sapphire Text size:minus plus Restore normal size   Mail page  Print this page
224
A POPULAR TREATISE ON GEMS.
the corundum cleaves in three directions of its jrimitive angles; the emerald has a less specific gravity, as three to' four; the phosphate of lime and the tourmaline are also found in six-sided prisms; but in all these cases are the cleavage, hardness, and specific gravity the distinguishing characters. The transparent colorless corundum may be confounded with the diamond, topaz, aquamarine, white spinelle, and quartz; in these cases the specific gravity is the principal distinguishing character; the white corundum weighs 3.970, the diamond 3.520, aquamarine 2.7, spinelle 3.64, the topaz 3.4, and the quartz 2.634.
The emery or granular corundum is of an ash-gray, bluish-gray, and sometime brown color; is massive, and opaque or slightly translucent on the edges ; is very hard, and scratches easily glass and quartz; is found in a bed of talc, in mica slate, in rounded masses, in Naxos, Italy, and Spain, and in great abundance on the summit of Gunnech-dagh, near Gumeschkeny, about twelve miles to the east of Ephesus, and between Eskihissar and Males, in Asia Minor, and in Ochsenkop, near Schwarzenberg, in Saxony. It has been elaborately described by Professor J. Law­rence Smith, of Louisville, Ky., as to its power as a polish­ing material. He lias ascertained that they all contain more or less water, and that their specific gravity as well as their hardness depends upon the percentage of water therein contained; but the specific gravity of a sapphire, ruby, or emerald, which contains no water, is.4-06 to-4'08, and thatihey generally contain from 1'60 to 3-90 per ce'nt. of water. This difference does not result* from a decom­position of the mineral but from their formation; he proves that the presence of water in these minerals which influ­ences their hardness or specific gravity, was existing while they were on the point of crystallization, and his 'experi­ments with the emery from China and Asia Minor, have
Ch. 6: Sapphire Page of 515 Ch. 6: Sapphire
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