size. A price of forty dollars per carat 

 is an average one for a stone of not over 

 ten^carats and, as much larger stones are 

 comparatively common, the price does 

 not increase so rapidly as does that of 

 the ruby with an increase in size. 



The world's supply of sapphires comes 

 chiefly from Siam. The most im- 

 portant mines of that country are 

 those of Battambong, a city south- 

 east of Bangkok. The sapphires oc- 

 cur in a sandy clay out of which 

 they are washed. The sapphire-bearing 

 region is about a hundred miles in length. 

 Together with the sapphires occur some 

 rubies, especially in the southern part of 

 the district. Sapphires also occur among 

 the rubies of Burmah, but in small num- 

 bers. The so-called gem gravels of Cey- 

 lon furnish many sapphires, though their 

 quality is not equal to those of Siam 

 because of paleness of color. In these 

 gem gravels occur also ruby, spinel, gar- 

 net, topaz, amethyst, tourmaline and hya- 

 cinth. Another locality for sapphires, 

 discovered in the early eighties, is Bans- 

 kar, in Cashmere, India. These stones 

 were first disclosed by the fall of an ava- 

 lanche, and later wxre discovered to ex- 

 ist in the region in considerable numbers. 

 For a time they could be . cheaply pur- 

 chased, but are now jealously guarded by 

 the government. The Montana sap- 

 phires have been known since 1865, but 

 were not systematically worked until 

 1891. They occur in river sands east of 

 Helena, and were first obtained in wash- 

 ing for gold. Now the m.other rock has 

 been discovered, and this is mined, the 

 rock being taken out, piled in heaps and 

 submitted to the action of frost through 

 the winter. The sapphires thus become 

 loosened and can be readily separated. 

 These sapphires are well crystallized and 

 are of good average size, though few 

 gems exceed six carats in weight. Their 

 luster and color are for the most part 

 of first quality, and the stones are in de- 

 mand for the best of jewelry. 



Noble Corundum of other colors than 

 those of blue and red is not of abundant 

 occurrence nor is it ordinarily as highly 

 prized as are the sapphire and ruby. Col- 

 orless sapphire or leucosapphire is some- 

 times used as a substitute for 'iheidiamond, 

 from which it can readilv be distin- 



guished b} its lower hardness and higher 

 specific gravity. 



Certain specimens of both sapphire and 

 ruby, but especially the former, exhibit 

 when lighted a six-rayed star. This ap- 

 pears as beams of light, radiating from a 

 center, which changes in position as the 

 stone is turned. Such stones are called 

 star or asteriated sapphires or rubies, and 

 are highly prized. They are usually cut 

 with rounded surface, as this best brings 

 out the figure. The cause of the star- 

 shaped figure is generally supposed to be 

 the presence of countless microscopic 

 cavities in the stone, which are arranged 

 parallel to the faces of a six-sid-ed prism. 

 The total reflection of the light from 

 these causes the star. Others think that 

 multitudes of twining lamellae cause the 

 appearance. 



Sapphire is a word which is the same 

 in nearh' all languages. In Chaldean, 

 Hebrew, Greek and Latin it has the same 

 form as in m.odem tongues. This fact 

 testifies to the ancient use of the stone. 

 In early times sapphire was believed to 

 be a destroyer of poison, so that if put 

 into a glass with a spider or venomous 

 reptile it would kill it. It was regarded 

 also as a remedy against fevers. 



SPINEL. 



The group of Spinel includes in min- 

 eralogy a number of species of different 

 though analogous composition. The 

 Spinel employed as a gem is almost 

 wholly confined to the magnesium alumi- 

 nate, having the percentage composition 

 alumina 71.8 and magnesia 28.2. This is 

 usually of a red color, different shades 

 giving gems known by different names as 

 follows : Deep red, spinel-ruby ; rose-red, 

 Balas ruby; yellow or orange-red- rubi- 

 celle ; violet red, almandine ruby. Spinel 

 is thus known among gems chiefly as a 

 relative of the ruby, and this sort of 

 Spinel w^ill first be considered. 



The Spinel rubies differ from the true 

 or corundum rubies in hardness, specific 

 gravity and system of cr3^stallization. 

 The hardness of Spinel is 8, or about 

 that of topaz, and the specific gravity 

 3.6. It is thus neither as hard nor as 

 heavy as corundum ruby. Again, the 

 system of crystallization differs. Spinel 

 crystallizes in the isometric system and 

 is usuallv found in the formi of octa- 



