|
Prehnite | As Chabasite.
|
Pycnite | Assumes a blue color, when treated with nitrate of
| cobalt. Gives the fluorine reaction with microcosmic
| salt.
|
Pyrope | Gives the chromium reaction with borax and microcosmic
| salt.
|
Scolecite | Similar to Laumonite, but more marked.
|
Scapolite | Occasionally contains a small quantity of lithia, and
| colors the flame red when fused with fluorspar and
| bisulphate of potassa.
|
Sodalite | If mixed with one-fifth its volume of oxide of copper,
| moistened to make the mixture cohere, and a small
| portion placed upon charcoal and heated with the blue
| oxidizing flame, the outer flame will be colored
| intensely blue from chloride of copper.
|
|
Spodumene | When not too strongly heated, colors the blowpipe
| flame red, when more strongly, yellow.
|
Stilbite | As Chabasite.
|
Topaz | When heated, remains clear. Otherwise as Pycnite.
|
Tourmaline | Gives the boracic acid reaction with flourspar and
| bisulphate of potassa.
|
Wollastonite | Colors the blowpipe flame faintly red from lime.
|
Zircon | The colored varieties become white or colorless and
| transparent, when heated. Is only slightly attacked
| by carbonate of soda.
______________|________________________________________________________

* * * * *

URANIUM.

* * * * *

Mineral. Pitchblende

Formula. [.U][...U=] essentially.

Behavior

(1) in glass-bulb. Evolves some water and a small quantity of
sulphur, sulphide of arsenic and metallic
arsenic.

(2) in open tube. Evolves SO^{2} and a white sublimate of
arsenious acid.

(3) on charcoal. Gives off arsenical fumes.

(4) in forceps. III. Colors the flame blue beyond the assay,
owing to the presence of Pb. Sometimes also
green towards the point, due to Cu.

(5) in