AMBLYGONITE. 



of the other sex. In common with other 

 stones the ancients attributed particular pro- 

 perties to Amber. Pliny states that it is 

 useful in medicine, and that a collar of Am- 

 ber worn round the neck of a young infant 

 was considered in his time a singular pre- 

 servative against secret poisoning, and a 

 countercharm to witchcraft and sorcery. 

 *' Callistratus saith, that such collars are 

 very good for all ages, and namely, to pre- 

 serve as many as weare them against fantas- 

 tical! illusions and frights that drive folke 

 out of their wits : yea and amber, whether 

 it be taken in drinke or hung about one, 

 cureth the difficultie of voiding urine." — 

 Pliny, book xxxvii. cap. 3. 



The modern name Amber is probably de- 

 rived from that by Avhich this substance is 

 known in the East ; anbar or anabar (^Per- 

 sian), anbaron {Arabic^. 



Amber is imitated by mixing by degrees, 

 at a moderate and gradually raised heat, 

 rectified oil of asphalt with turpentine in a 

 3'ellow copper vessel. When, after two or 

 three boilings, it has become sufficiently 

 thick, it is poured into moulds. 



Amber may be distinguished from Mellite 

 and copal, which are often substituted for it, 

 by spitting and frothing when burning, and 

 when its liquefied particles drop, by their 

 rebounding from the surface ou which they 

 fall; while Mellite does not fuse in the 

 same manner when heated, and copal,^when 

 heated at the end of a knife, takes fife and 

 melts into drops which flatten as they fall. 



Amber ornaments, when broken, may be 

 mended with cement composed of linseed 

 oil, gum mastic, and litharge, or by warming 

 the fractured surfaces and pressing them to- 

 gether, after they have been moistened with 

 a solution of potash, or soluble glass, — the 

 pieces being tied round with string for a few 

 days. 



Brit. Mus., Case 60. 



M. P. G. Horse-shoe Case, No. 92. 



Amblygonic Augite iiFAB.,lIaidinger ; or 

 Amblygonite, Breithaupt, Dana. Rhom- 

 bic. This mineral occurs massive and in 

 oblique rhombic prisms, which are rough 

 externally and of a greenish-white, a moun- 

 tain- or sea-green colour. Lustre vitreous, in- 

 clining to pearly. Translucent. Streak white. 

 Fracture uneven. H. 6. S.G. 3.0 to 3-11. 



Comp. Phosphate of alumina and lithia, 

 in combination with double fluoride of 

 aluminum and lithium ; represented by the 



formula (Ais ps + K^ps) + (A12 ps + RF) 

 where R stands for lithium, sodium, and 

 potassium. 



AMETHYST. 13 



Analysis by Eanunelsberg, from Camsdorf : 

 Phosphoric acid . . . 47*15 

 ■" " ... 38-43 



Alumina 

 Lithia . 

 Soda 

 Potash . 

 Fluorine 



7.03 

 3-29 

 0-43 

 8-11 



104-44 

 BB fuses readily with intumescence, and 

 becomes opaque white on cooling. Forms a 

 transparent colourless glass with borax. 

 Easily soluble in sulphuric acid. Occurs in 

 granite at Chursdorf and Arnsdorf near Pe- 

 nig, in Saxony, associated with Tourmaline 

 and Garnet : also at Arendal, in A'orway. 



The name is derived from oif/.Sxvyo:juo;, 

 having an obtuse angle ; (oif^Q^^v;, blunt, and 

 yojviM, angle). 



Brit. Mus., Case 54. 



Amethyst. A variety of Quartz of a 

 clear purple or violet-blue, of various de- 

 grees of intensity ; the colour not unfre- 

 quently passing, in the same specimen, from 

 the richest tint to almost colourless. The 

 colour is supposed to be produced by the 

 presence of a small per centage of man- 

 ganese. Heintz, however, on analysing a 

 very deep purple specimen from the Brazils, 

 obtained in addition to silica, 0*0187 pro- 

 toxide of iron, 0-6236 lime, 0-0133 magnesia, 

 and 0-0418 soda ; whence he infers that the 

 colour is due to a compound of iron and 

 soda. The finest Amethysts are brought 

 from India, Brazil, Ceylon, Persia, Morocco, 

 and Siberia ; but inferior, though beautiful 

 specimens are found in Transylvania, Hun- 

 gary, Saxony, the Harz, Brioude in Au- 

 vergne, Murcia and Catalonia in Spain. A 

 vein of Amethyst of a very beautiful colour 

 is said to exist at Kerry Head, in Ireland, 

 and many years ago it was used for jewelry. 

 (F. J. Foot.) It occurs massive, in rolled 

 pieces, and in hexagonal crystals, which are 

 rarely so distinct as those of Quartz, being 

 generally united together for the entire 

 length of the prisms, so that only the p3Ta- 

 midal terminations are separated from each 

 other. For this reason, when broken in the 

 direction of the prisms, the fracture presents 

 a coarsely fibrous or wrinkled appearance, 

 somewhat resembling that of the skin on the 

 palm of the hand. All the varieties of Rock 

 Crystal having this peculiar wrinkled frac- 

 ture are classed by Sir David Brewster under 

 the head ofAmethyst, of whatever colour they 

 may happen to be. It is also found in veins, 

 or forming the interior coatings of Agates in 

 trap-rocks. The Amethyst varies consi- 

 derably in transparency. It has always 



