B E R 



336 



B E R 



t igle ; adjoining its most southern staircase is a gate 

 with a circular arch, on entering which on the right arc the 

 ruins of a number of vaulted buildings. The place u men- 

 tioned in Scottish history several times. Fast Castle, a 

 picturesque ruin, is also at a short distance south of Pcath's 

 bridge, on a precipice overhanging the sea. It was a fortress 

 of the Earls of Hume, and subsequently was the dwelling 

 of Logan of Restalrig, who was concerned in the Cowrie 

 con-piracy. The barony of Coldbrand's (otherwise Cock- 

 burn's) Path was attached to the Scotch earldom of March. 

 The parish of Earlston, originally Ercildoun, in thin county, 

 was the birthplace of Sir Thomas the Ryincr, celebrated 

 by Sir Walter Scott in his ' Minstrelsy of the Scottish Bor- 

 der,' and part of his tower or castle still remains, besides a 

 stone said to have covered his grave. Thirlstane Castle, in 

 the parish of Lander, was built by the celebrated Scottish 

 Chancellor Maitland. Eccles was the native parish of 

 Henry Home Lord Kames. In it there is a cross, gup- 

 posed to have been erected after the second Crusade, and 

 some remains of a nunnery. 



(A Map qf Berwickshire from Actual Survey, by John 

 Blackadder, Edinburgh, 1797; Third Report of the Emi- 

 gration Committee ; A General View of the County of Ber- 

 wick, by Robert Kerr, Edinburgh, 1813; Grose's Anti- 

 quitiei of Scotland, fol. edition; First Report of the 

 Salmon Fisheries' Committee; Second Ditto ; Third Ditto ; 

 Tablet of the Revenue Population, <f-c. of the United 

 Kingdom ; Enumeration Abstract of Population Re- 

 turns ; Chambers' s Gazeteer ; Sinclair's Statistical Ac- 

 count ; The New Statistical Account of Scotland ; 

 Cough's Camden, vol. iii. ; Chalmers's Caledonia, vol. ii. 

 pp. 198 395; Morton's Monastic Annals of Teviotdale ; 

 Playfair's Illustrations of the Huttonian Theory; Car- 

 lisle's Top. Diet, of Scotland, and Communications from 

 Btrwirkshire.) 



BERYL, a mineral species among the varieties of which 

 are found two of the most beautiful and costly gems with 

 which we are acquainted, namely, the emerald and the 

 precious beryl. Before entering into the particulars of these 

 varieties, which from their beauty and price have the 

 greatest claim on our attention, we will state the general 

 and scientific properties by which the whole species may be 

 recognised and distinguished from other minerals. 



They belong to the rhombohedral system of crystallization, 

 usually occurring in regular hexagonal prisms which occur 

 variously modified, sometimes by the truncation of the 

 lateral edges of the prism, at other times by the simple 

 truncation of the terminal edges ; but the prism is sometimes 

 terminated in a much more complicated manner, of which a 

 remarkable instance has presented itself in a crystal iu the 

 possession of Professor Naumann, of Freiberg, who has 

 observed in them the faces of no less than six other forms of 

 the rhombohedral system. For a full description of them we 

 must refer our reader to the Lehrbuch der Mineralogie of 

 that mineralogist, where, under the head of Smaragd, will be 

 found all the varieties of form which have been observed in 

 this mineral. It seems better in this instance to give rather 

 a popular than a strict description, when the latter would 

 force us into the use of symbols probably unintelligible to 

 the majority of our readers ; and the more particularly in 

 this case, as we believe attention to the following points will 

 be more generally useful in the determination of this crystal ; 

 namely, that its general aspect is always that of a hexagonal 

 prism, and that when the terminal edges are modified, there 

 will generally be found a plane inclined to the lateral planes 

 of the prism under an angle of 119 58'. 



The crystals admit of cleavage in the four directions 

 parallel to the faces of the regular prism, that parallel to 

 the terminal plane being perfect, the others imperfect and 

 more difficult to be obtained. The fracture is conchoidal 

 and uneven ; the lustre is vitreous, and it possesses various 

 degrees of transparency. According to Mohs, the hardness 

 varies from 7'5 to 8, the specific gravity from 2'678 to 2732. 

 The following are its chemical characters before the blow- 

 pipe, as stated by Berzclius. 



Alone it it not easily acted upon, but when thin frag- 

 ments are for a long time submitted to a powerful flame, 

 the edges become rounded and a colourless vesicular scoria 

 is produced. The transparent varieties become milky. 



With borax it forms a clear and generally colourless 

 glass, which effect is also produced by soda. With I lie 

 phosphor salt it is with difficulty dissolved without the for- 

 mation of a silicious skeleton. 



Hruclitbo. 



68'35 



17-60 



13-13 



0-72 



0*27 



O'OO 



O'OO 



Of this mineral we possess several analyses, of which the 

 following are three : the first being an emerald from Peru, 

 by Klaproth ; the second a beryl from SilH?ria, by the same 

 chemist : and the third a beryl 'from Broddbo, near Fahlun, 

 in Sweden 



Kmrnlil. T*. 



Silica . . 68-50 66-45 



Alumina . . 15-75 16-75 



Glucina . . 12*50 15'50 



Oxide of iron . TOO 0'60 



Oxide of columbium O'OO 0-00 



Oxide of chromium 0'30 O'UO 



Lime . . 0-25 O'OO 



From his analyses Berzelius has adopted the formula 

 G Si* + 2 Al Si* to represent the atomic constitution of 

 this mineral ; Naumann and Beudunt, however, consider it 

 to be as follows : 



G Si" + 2 Al Si'. 



This species contains several varieties, of which the two 

 known among lapidaries under the name of emerald and 

 aquamarine, or precious beryl, are the most worthy of at- 

 tention. These varieties, though distinguished by some 

 mineralogists as forming distinct species, differ, howe\er, 

 only in colour, the term emerald being applied to those 

 possessing the peculiar rich, deep green, so well know a as 

 the emerald-green, while all the other varieties are com- 

 prehended under the name of beryl ; those which are clear, 

 transparent, and possess a good colour, present various 

 shades of sky-blue or mountain-green, being the aqua- 

 marine or precious beryl. The colour of the emerald in 

 attributed to the small quantity of green oxide of chromium 

 which has been found in the specimens from Peru ; while 

 the varieties in the tints of beryl may be considered to be 

 produced by admixtures of the oxides of iron, the yellow 

 being the colour of the peroxides of iron, and the mountain- 

 green and the various shades of blue being the effect of 

 varying quantities of the protoxide, to the presence of which 

 the common bottle-glass owes its tint. 



The following localities produce the finest emeralds : the 

 mines in the Tunea Valley, situated in the mountains be- 

 tween New Granada and Popayan, and not far from the 

 town of Santa F6 de Bogota, where, according to Huraholdt, 

 they are found in veins traversing clay-slate, hornblende 

 slate, and granite ; the Heubach valley, in the district of 

 Pinzgau. Salzburg, where they occur imbedded in mica- 

 slate, and are inferior in colour to those from Peru : varieties 

 have also been lately found in some old mines in Mount 

 Zabarah, in Upper Egypt, from which spot the antients are 

 supposed to have derived their emeralds. 



The varieties known by the name of beryl are found prin- 

 cipally in Siberia and Brazil : in the former country it occurs 

 in the granite district of Nertschinsk, and also in the Uralian 

 and Altai mountains, sometimes in very large crystals, prints 

 having been found upwards of a foot in length. In the 

 granitic mountains of Odon Tchelon, in Da-uria, three very 

 interesting mines occur at different elevations in the moun- 

 tain; in the lowest are found, irregularly disseminated 

 through a mass of semi-decomposed granite mixed with 

 ferruginous clay and nodules of Wolfram, prismatic crystals 

 of beryl of a greenish-yellow colour, rarely exceeding one 

 inch in length. Some hundred feet higher occurs the 

 second mine in a vein of micaceous clay, from which the 

 most valuable crystals are obtained; their colour is .-I' 

 a pale but pure green, and their si/.e frequently consider- 

 able. The third mine is situated in a vein of white indu- 

 rated clay on the summit of a mountain ; in this mine llie 

 varieties are usually of a pale greenish-blue, but sometimes 

 they are found of a pure but pale sky-blue. They are here 

 remarkably transparent. Imbedded crystals and m:<- 

 varieties are also found at Limoges, in France : near 

 Zwiesel, on the Rabenstein, in Bavaria ; at Fimbo and 

 Broddbo, near Fahlun, in Sweden ; and likewise in some of 

 the tin mir.es in Saxony and Bohemia. 



An enormous specimen i- al-o described in Silliman's 

 .7 'iirtnit, as Iia\ing been found at Arworth, in New Hamp- 

 shire, United States. Its dimensions are stated to be four 

 I,- l m length and five inches and a half across the literal 

 planes, and the weight to be 238 Ibs. 



Specimen- of beryl have also been found in several of the 

 primary districts of Ireland ; those from the granite of the 



