CATALOGUE OF GEMS AND PRECIOUS STONES. 193 



Oriental 8raaragd=green corundum. 



Oriental sunstone=girasol (corundum). 



Oriental topaz=yellow corundum. 



Oriental turquoise=turquoise. 



Orthoclase= potash feldspar in monoclinic crystals, aluminum and potassium silicate. 



Orthose= moonstone (feldspar). 



Ouachita stone=novaculite (whetstone); quartz. 



Ouvarovite=emerald-green garnet colored by chromium. 



Ox-eye=labradorite (feldspar). 



P. 

 Pagoda stone =agalmatolite. 

 Pagodite=agalmatolite. 

 Paphos diamond = quartz. 



Parisite= cerium carbonate (and other rare elements), with fluorine. 

 Paste=artificial lead glass used to imitate gems. 

 Paul ite = hy perstene . 



Pealite=opal-like variety of geyserite (silica). 

 Pearl =lustrous calcareous concretion with animal membrane between successive 



layers, deposited in the shells of various mollusks. Not a mineral but an animal 



product. 

 Pearlite=a form of obsidian. 

 Pebble=rock crystal (quartz) . 

 Pecos diamond = quartz from Pecos River, Texas. 

 Pectolite=calcium and sodium hydrous silicate. 

 Pegmatite = coarsely grained rock composed of quartz and feldspar. 

 Pelhamite= variety of serpentine. 

 Peliom = cordieri te. 

 Pennsylvania diamond =iron pyrite. 



Peridot of Ceylon =same as Ceylon peridot, honey-yellow tourmaline. 

 Peridot=olivine. (See Olivine.) 

 Peristerite=iridescent albite (feldspar). 

 Persian lapis = lapis lazuli. 

 Perthite= potash feldspar (orthoclase or microcline) with laminae of soda feldspar 



(albite). 

 Peruvian emerald = the best emeralds from Muzo, Colombia. 

 Petoskey agate = cemented portions of fossil coral (beckite). 

 Petrified honeycomb = beckite. 

 Petrified wood=wood replaced by silica. 

 Phenacite=silicate of beryllium. 

 Phenomenal gem=one which shows a play or change of color by artificial light, or 



shows a movable line of light. 

 1 L-dmontite= brownish-red variety of epidote. 



Pin fire opal=opal in which the area of the individual colors is very small. 

 Pink topaz=topaz either naturally pink or artificially colored pink by heating the 



yellow or brown varieties. 

 Pink wollastonite=lilac-colored pyroxene (diopside) from the region of San Francisco, 



California . 

 Pipestone =catlinite (compacl red day). 

 Pisolite=concretionary massive limestone similar to oolite but made up of larger 



spherical grains. 

 Pistacite=greenish epidote. 

 Pitch opal=bro\vn opal with a pitchy luster. 

 Pitchstone=ob8idian of a pitchy luster. 

 4555—22 15 



