NEOLITE. 



_^ Comp. Hydrated arseniate of iron, or #e 

 AS+4H. 



Analysis, from Brazil, by Berzelius : 

 Arsenic acid . . . 50-78 



NEPHELINE. 



2o7 



Peroxide of iron . 



Phosphoric acid . 



Oxide of copper . 

 Water 



. 34-85 

 . 0-67 

 . trace 

 . 15'o5 



101-85 

 BJB gives off moisture when heated, and 

 turns yellow. Imparts the colour of iron to 

 the fluxes, and emits a strong odour of 

 arsenic. 



Name. From nU^ new, and ^r-^-ri?, acqui- 

 sition. 



Xeolite, Scheerer. A massive varietv 

 of Talc, in which a portion of the silica is 

 replaced by alumina. Occurs either in small 

 ci-ystalline laminsB and silky fibres grouped, 

 or in apparently an amorphous state. Colour 

 brownish- and blackish -green,passing almost 

 into black. Lustre silky or earthy. Unc- 

 tuous to the touch, and may be" cut like 

 soap. H. : the crystalline variety is nearly 

 as hard as Talc ; the amorphous"^ varietv fs 

 softer. S.G. when perfectly dry 2-77. 



Comp. E Si, or (Fe Mg) Si +H nearly. 

 Analysis (mean of two), by Scheerer : 

 . 48-81 



Silica 



Alumina 



Magnesia . 



Protoxide of iron 



Lime . 



Protoxide of manganese 



. 8-75 

 . 27-99 

 . 5-86 

 . 0-14 

 1-75 



Water 5-10 



99-52 

 Loses water and becomes nearlv white at a 

 temperature of 100°. When dried and im- 

 mersed in water gives out bubbles of air, 

 and reabsorbs water so rapidly as to fall in 

 pieces soon after immersion. 



Locality. Aslak Iron Mines, near Arendal 

 in Norway. 



Name. From ^'M, new, and A/fo,-, stone, in 

 allusion to the belief in its being newly 

 formed by the infiltration of waters which 

 have passed over rocks containing magnesia. 

 ■ Neoplase, Beudnnt. From vso?, new, and 

 ^Kaa-n^ formation. See Botryogeke. 



Neotokite. Probably an altered form 

 of Khodonite, allied to Stratopeite. Amor- 

 phous. Colour black to brownish-black. 

 Opaque or feebly translucent. Streak brown 

 H. 3-5 to 4. S.G. 2-7 to 2-8. 



Comp. Mg Si + (Mn Fe). Si + 8H. 



BE yields water, but is infusible. 



Locality. Gaosbole in Finland. 



Name. From no;, new, and roxo;, a birth. 



Neotype, Breithaupt. A varietv of Calcite 

 containing Baiytes. S.G. 2*82 to''2-83. 



jSame. From veo?, new, and ri^s-e?, a form 

 or type. 



Nepheline, Haiiy. Hexagonal. Occurs 

 crystallized in regular six-sided prisms (the 

 primary form), which have their terminal 

 edges sometimes replaced; also compact, 

 massive, and columnar. (See Ei^eolite.) 

 Colourless, or greyish-white : when massive 

 greenish or bluish, brownish and brick-red. 

 Lustre \itreous, shinmg. Transparent to 

 opaque. Brittle. Fracture subconchoidal. 

 H. 5-5 to 6. S.G. 2-5 to 2-6. 



:;?, 



Fig. 310. 



Fig. 311. 



Fig. 312. 



Comp. (K Na) Si + A\ Si or K Si2 -f ^i 

 Si + 5Ai si (Scheerer). 

 Analysis, from Vesuvius, by Scheerer : 



Silica 

 Alumina 

 Peroxide of iron 

 Soda . 

 Potash 

 Lime . 

 Magnesia . 

 Muriatic acid 

 Sulphuiic acid 

 Water . 



44-04: 



34-06 

 0-44 



15-91 

 4-52 

 2-01 



trace 

 0-14 

 0-14 

 0-21 



101-38 



BB fuses to a colourless blistered glass. 



In fragments in nitric acid, the latter be- 

 comes turbid. In a powdered state, com- 

 pletely decomposed by muriatic acid, and 

 converted_ into a gelatinous mass. 



Localities. Monte Somma, in fine white 

 crystals in cavities of the older lavas, with 

 Idocrase, Mica, Hornblende, &c. Capo di 

 Bove, near Rome, in lava. Katzenbiichel, 

 near Heidelberg, in clinkstone. 



Name. From v£(?fA-^, a cloud; in allusion 

 to the clouded appearance assumed by a 

 translucent fragment when immersed in 

 nitric acid. 



Brit. Mus., Case 31. 



