188 BULLETIN 118, UNITED STATES NATIONAL MUSEUM. 



Haiiynite= complex aluminum, calcium, sodium, and potassium silicate with the 

 sulphate radicle. 



Hawk eye=quartz with inclusions of fine blue parallel fibers of crocidolite. 



Heliodor=beryl from Rossing, Africa; contains a small amount of uranium and is 

 weakly radioactive. By daylight gold-yellow, by artificial light a delicate blue- 

 green. 



Heliolite=sunstone (feldspar). 



Heliotrope = bloodstone (quartz). 



Hematite=iron oxide, either black or red. 



Hemimorphite= calamine (English usage). 



Hercynite=black to dark-green spinel composed of aluminum and iron oxides. 



Herkimer diamond=clear quartz crystal from Herkimer County, New York. 



Hessonite=variety of grossularite (garnet). 



Hetaerolite=brilliant-black radiated mineral composed of the zinc and manganese 

 oxides. 



Hiddenite=green or yellowish-green spodumene. 



Horatio diamond =colorless quartz from Arkansas. 



Hornblende=aluminum, iron, calcium, magnesium silicate, and other elements. 



Hornstone=compact form of silica, like flint but more brittle. 



Hot Springs diamond = quartz. 



Howdenite=chiastolite with fernlike markings, from South Australia. 



Hungarian cat's-eye=quartz cat's-eye. 



Hyacinth=red zircon; also wrongly applied to essonite or other light-colored garnets, 

 to yellowish-red spinel from Brazil, and to red iron-stained quartz. 



Hyacinth of Compostella=quartz, with red hematite inclusions. 



Hyacinthozontes=sapphire-blue beryl. 



Hyalite=clear and colorless opal. 



Hyalosiderite=rich olive-green olivine, containing much iron. 



Hydrophane=opal which becomes transparent in water. 



Hypersthene= magnesium and iron silicate, variety of enstatite. 



I. 



Iceland agate=obsidian. 



Iceland spar=clear calcite. 



Iceland agate la va= obsidian. 



Ichthyophthalmite=apophyllite. 



Idocrase=vesuvianite. 



Ilmenite=black iron and titanium oxide. 



Image stone=agalmatolite. 



Imperial jade (Chinese) =green, aventurine quartz. 



Imperial yu-stone= green aventurine quartz. 



Ilvaite=iron and calcium hydrous silicate. 



Inca stone=pyrite. 



Indian agate = moss agate. 



Indian topaz =8affron-yellow topaz; also yellow quartz. 



Indicolite=blue tourmaline. 



Iolanthite== jasper from Crooked River, Crook County, Oreg. 



Iolite=cordierite. 



Iridescent quartz =rock crystal (quartz) filled with fine cracks containing air films 



which reflect the colors of the rainbow. 

 Iris=iridescent quartz; also applied to other iridescent minerals. California iris is 



spodumene. 

 Irish diamond = quartz crystal from Ireland. 

 Iron glance=hematite. 



