MINERALOGY. 



Natron, Smtde carlonatee, Fr. Native carbonate of foda 



11.. i^,r fiv fided nx-ramids. iihrfR.O'S^Smde earbmaiee, Mr. JNative carbonate of foda 

 fided prifm, terminated by two low ">;- jf/^^giinr is depofited on the fides of lakes, or on the furface of the 

 The luftre is metallic and (hining. i he tructurc ■» , r, ^ ,, ^._. ._ . jr, , . r 



^ "ll"l"^vithVhe lateral planes of the ground, and generally containing muriate and fnlphate of 



^''^ ^ - . , . i./i:. foda. See Soda. 



Radiated Natron, Sonde carbonatee ackuhi'ire, Fr. occurs in 

 Africa, and forms a confiderable article of commerce. This 

 variety is nearly pure carbonate of foda, containing, accord- 

 'ng to Klaproth, 



•^" J ,., , , u„f /^n white norcelain it mais.es a 



paper hke P^^-b^S^'^' fie gravity I from 4-5 to ^-l- 

 rr thT li'w P ie it g ' o?.t a fulphureous odour, and 

 Sw-rtdtyth^utmofl force, .t y .elds a white vapour 

 and a pi blue flame ; m carbonate of foda, it is foluble 

 with violent effervefcence. The characters here g-en, par- 

 Sarly ts mark on china, ferve to diftinguifh molybdena 

 K Uaphite and plumbago. (See M0Z.VBDENUM, and 

 Sulphur ) According to Bucholz, its conftituent parts 



Molybdenum 

 Sulphur 



60 



40 



100 



This mineral occurs in fome parts of Scotland, and m 

 granite at Coldbeck-fell in Cumberland. It is found alfo 

 at Huel-Gorland, Cornwall. _ . , 



MoLYBDEN-A Ochre is a yellow colour, paffing into yel- 

 lowifli-green ; it is friable and dull, and occurs incruftmg 

 molybdena, on which it is doubtlefs formed by the decom- 

 pofition of the latter mineral. 



MooN-sTOXE, a variety of adularia. See Adularia, and 



Felspar. 



MoRASs-Om See Bog Iron-Ore. 



Mountain Cork, or Mountain Leather; JJheJle irejjl; 

 Haiiy. It is fometimes called mountain flefia and mountain 

 pader. It occurs in thin flexible plates like leather, or in 

 thicker and lefs flexible pieces like cork-wood. The colours 

 are yellowifh and greyifh-white ; it yields to the nail, is 

 meagre to the touch, and fo light as to fwim on water 

 The ftrufture is finely and promifcuoufly fibrous. '^ ■^ 

 ing to Bergmann, its conilituent parts are. 



Water of cry ftallization 

 Carbonic acid 

 Pure foda 

 Sulphate of foda 



Nepiieline, or 5'ammiVi'. (See Sommite.) This mineral 

 occurs in the lava of Vefuvius, and bears a near refemblance 

 to Meionite (which fee). Nepheline is cryllallized in 

 fix-fided prifms or tables, but the cryftals of meionite are 

 four-fided prifms. The latter mineral is eafily fufiblc, but 

 nepheline melts with difficulty. Nepheline has a four-fold 

 cleavage, three of which are parallel with the lateral planes, 

 and one to the terminal planes of the prifm. Tranfparent 

 pieces ot nepheline become cloudy in nitric acid ; hence it 

 was named by Haiiy from the Greek word ii^piXr., a cloud. 



Nephrite, or Jade; Jade nephrit'tque, Haiiy. The 

 colour is leek-green, paffing to greyifh-green ; it occurs 

 maffive. The frafture is uneven and fplintery, with a glim- 

 mering and fomewhat grcaly luftre ; it is tranllucent. 

 Nephrite yields to the knife, but fcratches glafs ; it has a 

 greafy feel, is very tough. The fpecific gravity is froin 

 2.9 to 3. Before the blow-pipe, it melts into a white ena- 

 mel. According to Kaftner, its conftituent parts are, 



Silex 



Accord- 



Silex 



Magnefia 



Alumine 



Lime 



Oxyd of iron 



56.2 

 26.1 



2 

 12.7 



3 



100 



Alumine 



Magnefia 



Iron 



Chrome 



"Water 



50 

 10 



31 

 5.50 

 0.05 



2-75r 



99-3° 



Mountain, or Rock Wood, or L'tgnlform Apejlus ; AJ- 

 lejle ligniforme, Haiiy ; has a wood-brown colour, and a 

 curved and fibrous llrufture refembling wood. It is foft, 

 opaque, and feftile ; it is flightly flexible ; it feels meagre. 

 According to Jamefon, it is infufible ; it is clafied by him 

 in the tale family. 



See Hyalite. 



Nephrite occurs in granite veins in the Hartz in Saxony ; 

 the moft beautiful varieties are from Perfia and Egypt. In 

 Turkey it is cut into iiandles for fabres and daggers. It 

 was formerly believed that this ftone ^had the property of 

 relieving nephritic complaints ; hence it has been called 

 nephritic ftone. A flaty kind of nephrite is ufed by the 

 inhabitants of New Zealand for hatchets, and hence has been 

 called axe-ftone. Nephrite is nearly allied to ferpentine and 

 fteatite ; there is alfo a kind of nephrite which is more nearly 

 allied to felfpar, and is claffed by Mr. Jamefon with the 



MULLER Glafs 



'M.VRlAT^ of Ammonia, Native, is a frequent produft of felfpar family; it is called fauffurite, after the celebrated 



volcanoes. See Ammonia. 



Muriate of Copper. See CopPEH-Ores. 



Muriate of Lead, or Corneous Lead-Ore. See Lead- 

 Ore. 



Muriate of Soda. See RocK-Salt and Salt. 



Muscovy' Glafs, the large plates of mica, which are 

 generally brought from Siberia. (See Mica.) Thefe 

 plates are erroneoufly called talc 



MussiTE, a variety of Diopside ; which fee. 



Naphtha, Bitume liquide blanchatre, Hauy. See Bi- 

 tumen. 



Natrolite, See Natkolite, and Zeolitf, 



geologift Saufliire, by whom it was firft difcovered. See 

 Saussurite, Addenda. 



NiCKEL-0/-« are, native nickel, copper nickel, and nickel 

 ochre. 



Native Nickel has only been found hitherto in the 

 Adolphus mine at Johanngeorgenftadt in Saxony, and at 

 Joachimrtal in Bohemia. Its colour is bronze-yellow, but 

 is frequently tarniflied greeni(h-grey, or fteel or lead-grey, 

 and occafionally inverted with a cruft of brown iron-itone. 

 It occurs in capillary cryftals, which are either promifcu- 

 oufly or fcopiformly aggregated. Internally the luftre is 

 fplendent and metallic, externally Ihining" or fplendcnt when 



untarniflied. 



