CATALOGUE OF GEMS AND PRECIOUS STONES. 189 



Isle of Wight diamond = quartz crystal. 



Isle Royal greenstone=chlorastrolite. 



Isopyre=very impure opal. 



Italian chrysolite=vesuvianite. 



Iztac Chalchilmitl = \vhite or green Mexican onyx. 



Jacinth= yellow zircon, also improperly applied to essonite and other yellowish 

 garnets. 



Jade=two minerals, nephrite and jadeite. True jade is nephrite; many other miner- 

 als are also called jade, such as pectolite, vesuvianite, garnet, bowenite, serpen- 

 tine, plasma, prehnite, agalmatolite, sillimanite, and saussurite (a rock). 



Jadeite=greenish aluminum and sodium silicate (pyroxene). 



Jager=bluish-white diamond of modern cut. Originally referred to diamond from 

 the Jagersfontein mine, South Africa. 



Jargon=white or grayish-white zircon. 



Jargoon = jargon . 



Jasp agate = intermediate between jasper and chalcedony with predominant opaque 

 jasper. 



Jasper = massive quartz, impure and opaque, containing more iron oxide than agate. 



Jasper opal=deeply colored opal with many included impurities. 



Jasperine= banded and variously colored jasper. 



Jet= pitch-black or velvet-black coal sufficiently hard and compact to receive a bril- 

 liant polish. 



Job's tears=local name for peridot from Arizona and New Mexico; also hyalosiderite, 

 a rich olive-green olivine. 



K. 



Kashmir sapphire = cornflower-blue corundum. 



Keystoneite=blue chrysocolla or chalcedony colored by copper silicate. 



Kidney stone = nephrite. 



Killiecrankie diamond =limpid topaz from Tasmania. 



King topaz=clear pink, orange, red, yellow, or flesh-colored corundum. 



Kinradite= jasper with spherulites of quartz, from the region around San Francisco, 



California. 

 Kornerupine= aluminum and magnesium silicate. 

 Kunzite=transparent lilac spodumene. 

 Kyanite= aluminum silicate. 



L. 

 Labrador feldspar=labradorite. 

 Labrador hornblende=hypersthene. 

 Labrador spar=labradorite. 

 Labrador stone=labradorite. 



Labradorite=feldspar, aluminum, sodium, and calcium silicate. 

 Lake George diamond=clear quartz crystal from Herkimer, New York. 

 Lake Superior greenstone=chlorastrolite. 

 Lapis lazuli=rock composed essentially of the minerals lazurite, haiiynite, scapolite, 



calcite, pyroxene, amphibole, mica, and feldspar. 

 Lava=volcanic rock. 

 Lavendine= amethyst (quartz). 



Lazulite=blue aluminum, iron, and magnesium hydrous phosphate. 

 Lazurite=blue aluminum, calcium, and sodium silicate, with the sulphate radicle. 

 Lechosos opal=opal showing deep-green flashes of color or specked with green and 



carmine; also used for milky opal. 



