|
|||||
|
Zircon appears to have been first discovered by Klaproth in 1789, in the form of an earth, and six years later he found that the stone hyacinth contained a similar substance, both having the formula, ZrSiO4, and both having as their colouring agent ferric oxide. There are several methods of obtaining the metallic element, [...] There are certain stones and other minerals which, owing to their possession of numerous microscopically fine cavities, of a globular or tubular shape, have the appearance of “rays” or “stars,” and these are called “asteriated.” Several of such stones have been discussed already in the last chapter, and in addition to these star-like rays, [...] |
 |
|||
Copyright © 2012 Crystal and stones - All Rights Reserved |
|||||
